MICROSKILLS INFORMATION TECHNOLOGY TRAINING FOR WOMEN PROGRAM (ITTW)

MICROSKILLS INFORMATION TECHNOLOGY TRAINING FOR WOMEN PROGRAM (ITTW)

Hardware

Software

Networks

Local Area Network (LAN)

Wide Area Network (WAN)

Wireless Local Area Network (WLAN)

Remote Access

Virtual Private Network

Internet

Email

Websites

Web Browsers

Search Engines and Directories

Security

INFORMATION TECHNOLOGY BASICS

INTRODUCTION

Information Technology involves the processing of information by a computer. Usually this means the use of hardware, software, services, and the supporting infrastructure to manage and deliver information.

1. HARDWARE 
Hardware can be defined as IT-related machinery and equipment. This would include physical machines such as personal computers (PC's), storage devices (such as CD's) and cables etc. In order to operate however, a computer uses software - hardware and software are interdependent.

Hardware is the physical unit which stores and transmits information.

Software is the logic and language that dictates how this is done (see Software below).

Until the late 1970's, most word processors were dedicated machines e.g. typewriters. Now computers have replaced almost all dedicated word processors. However in order to be able to work with text, a PC, which is hardware, requires a set of instructions, which is software that provides word processing functions on the PC.   Popular word processing software packages are Microsoft Word and WordPerfect.

The amount of work that a computer can do is dependent on the size of its memory and the speed that it can operate at.

Memory When you see an advertisement for computers, RAM is often mentioned. This means Random Access Memory and defines the computers capacity for work. Memory is like an electronic checkerboard, with each square holding one byte of data or instruction. When personal computers first came on the market in the late 1970s, 64 kilobytes (64 KB) of RAM was the upper limit. Today, 64 megabytes (64 MB) of RAM is entry level (the starting point) for a desktop computer i.e. a thousand times as much.

CPU- Central Processing Unit
The speed at which a computer operates is dictated by the Processor in the Central Processing Unit (CPU), which is the processing part of the computer. The CPU, clock and main memory make up the basic computer.

A complete computer system needs other elements such as the control units, input devices (e.g. keyboard), output devices (e.g. screen), storage devices and an operating system (the master control program that runs the computer). Any hardware device connected to a computer, such as a monitor, keyboard, printer, disk, tape, graphics tablet, scanner, joy stick, mouse etc. is known as a peripheral device.

O/S - Operating System

The Operating System (O/S) is the first program (set of instructions) to come to life when the computer is switched on. Its main part, the 'kernel,' is kept in the memory at all times. The operating system is the link between the hardware and the application programs that run in the computer. The applications 'talk to' the operating system for all user activity and file management operations.

Operating Systems that you have probably heard of include

various versions of Windows (95, 98, NT, XP etc.),

the Unix versions (Solaris, Linux, etc.),

the Macintosh OS,

the AS/400's

There are many more. Does anyone remember DOS - with its tiny text on a dark screen? DOS is still used as an Operating System for some applications. There are other special-purpose operating systems.

Storage Devices

Storage devices are the temporary or permanent holding place for digital information. It refers to disks and tapes, for example where information is stored - think of it as having extra physical space in a warehouse. Memory is not a storage device - it is a temporary workspace that the computer uses to execute tasks, such as processing information.

Hardware requirements depend on the size of the databases that will be created and the number of users or applications that will be served at the same time. How much? How fast?

Trends in Hardware

Portable PCs

One clear trend in hardware development is the move towards portability. Portable PC's such as laptops and notepads (different suppliers label portable PC's in different ways) are becoming more popular.

The advantages of portable PC's are many - business people can work from home, the airport or at any workstation in the office without the need for a fixed location. This can improve productivity and even reduce office overheads as the need for fixed workstations diminishes. Portable PC's also facilitate Internet access from remote locations giving access to information regardless of where the user is situated (as long as an Internet connection can be established in that location) is also makes it easier for the employee and can reduce overheads

However, portable PCs are more expensive - in some cases significantly so - than Desktops. Also where there is no power source, the user is dependent on the life of the battery, which can be limited, typically for 1.5 to 2 hours and possibly less depending on the age of your machine, the model etc..

PDAs Personal Digital Assistants

Another growing trend in hardware is the development of various other small portable devices which have much of the power of a computer, are connected by radio links to the Internet but are generally smaller and are used by service engineers, sales people, truck drivers etc. These are called Personal Digital Assistants (PDAs). iPAC and PalmPilot are well known brands in this marketplace - the line between these devices and mobile phones is slowly blurring over time.

2. SOFTWARE
Software can be defined as the set of instructions for the computer - it dictates what is to be done. Software runs on (i.e. operates on) hardware. A list of instructions that undertakes a particular requirement or task is known as a 'program.' The two major categories of software are 'system software' and 'application software.'

System software is made up of control programmes for the computer itself, such as the operating system and database management system (DBMS).

Application software is any programme that processes data for the user (e.g. inventory, payroll, spreadsheets, word processors, etc.).

Often people confuse software with data however it is not data - it tells the hardware how to deal with the data - in simple terms software is 'run' (i.e. a set of instructions is initiated) and data is then processed. The data itself often comes in the form of databases - which are files that are originated and managed by a database management system (DBMS). DBMSs can manage data in many different formats such as text, sound, images and video. Database and file structures are determined by the software being used.

3. NETWORKS
A network is a group or a number of computers and other hardware and devices linked or connected together, physically.

LAN LOCAL AREA NETWORK

A Local Area Network (LAN) is common in business and it serves users within a confined geographical area.

Networking an office involves connecting each individual piece of hardware and software - for example your PC's, printers, fax machine, scanner and phone to pass and share information.

Equally, software applications such as your wordprocessing package e.g. Microsoft Word, can be accessed across the network.

Example

Here's how a basic network could work; if there are 4 people in your office and you are the only person that has a printer, each time one of your colleagues wants to print a document they have to email it over to you or get up from their desk, walk over to you and hand you a disk to print from.

Why not share that printer with your colleagues by networking the 4 computers together. Now they can print directly to your printer through the network without disturbing you or wasting time walking across the office to give you the disk to print. However there is a flaw in the above scenario in that the PC, to which the printer is attached, controls the printer. This means that the PC must be constantly switched on for the printer to work.

Network Interface Card

Alternatively, you can have a printer connected directly to the network by means of a Network Interface Card [NIC] in exactly the same way as a PC is linked to the network. In this way, the printer is independent of all the PCs on the network.

Most PC's now have Network Interface Card's included therefore they do not have to be bought for the network. If your PC is not new, you may need to purchase a Network Interface Card [NIC].

Router

A router is a computer networking device that forwards data packets across a network toward their destinations, through a process known as routing. Routing occurs at layer 3 (the Network layer e.g. IP) of the OSI seven-layer protocol stack. A router acts as a junction between two or more networks to transfer data packets among them. A router is different from a switch. A switch connects devices to form a Local area network (LAN).

Switch

A switch is a device for changing the course (or flow) of a circuit. The prototypical model is a mechanical device (for example a railroad switch) which can be disconnected from one course and connected to another. The term 'switch' typically refers to electrical power or electronic telecommunication circuits. In applications where multiple switching options are required (e.g., a telephone service), mechanical switches have long been replaced by electronic variants which can be intelligently controlled and automated.

One easy illustration for the different functions of routers and switches is to think of switches as neighborhood streets, and the router as the intersections with the street signs. Each house on the street has an address within a range on the block. In the same way, a switch connects various devices each with their own IP address(es) on a LAN.

The switch is referred to as a 'gate' when abstracted to mathematical form. In the philosophy of logic, operational arguments are represented as logic gates. The use of electronic gates to function as a system of logical gates is the fundamental basis for the computeri.e. a computer is a system of electronic switches which function as logical gates.

Ethernet hub

An Ethernet hub or concentrator is a device for connecting multiple twisted pair or fibre optic Ethernet devices together, making them act as a single segment. It works at the physical layer of the OSI model, repeating the signal received at one port out each of the other ports (but not the original one). The device is thus a form of multiport repeater. Ethernet hubs are also responsible for forwarding a jam signal to all ports if it detects a collision.

Internet Access
In terms of Internet access, to send and receive external email and surf the Internet you need a router, which acts as the buffer between your network and the outside world.

So for example, a router at home connects the Internet Service Provider's (ISP) network (usually on an Internet address) together with the LAN in the home (typically using a range of private IP addresses, see network address translation) and a single broadcast domain. The switch connects devices together to form the LAN. Sometimes the switch and the router are combined together in one single package sold as a multiple port router.

WIDE AREA NETWORK (WAN)

A wide area network or WAN is a computer network covering a wide geographical area, involving a vast array of computers. This is different from personal area networks (PANs), metropolitan area networks (MANs) or local area networks (LANs) that are usually limited to a room, building or campus. The most well-known example of a WAN is the Internet.

WANs are used to connect local area networks (LANs) together, so that users and computers in one location can communicate with users and computers in other locations. Many WANs are built for one particular organization and are private. Others, built by Internet service providers, provide connections from an organization's LAN to the Internet.

WANs are most often built using leased lines. At each end of the leased line, a router connects to the LAN on one side and a hub within the WAN on the other.

Leased lines can be very expensive. Instead of using leased lines, WANs can also be built using less costly circuit switching or packet switching methods. Network protocols including TCP/IP deliver transport and addressing functions.

For security, a firewall is required to filter data as it passes over the public network to prevent unsolicited access.

WIRELESS LOCAL AREA NETWORK (WLAN)

A wireless LAN or WLAN is a wireless local area network, which is the linking of two or more computers without using wires. It uses radio communication to accomplish the same functionality that a wired LAN has. WLAN utilizes spread-spectrum technology based on radio waves to enable communication between devices in a limited area, also known as the basic service set. This gives users the mobility to move around within a broad coverage area and still be connected to the network.

This technology is becoming more and more popular, especially with the rapid emergence of small portable devices such as PDAs (personal digital assistants).

Architecture of a Wireless LAN

Stations

All components that can connect into a wireless medium in a network are referred to as stations. All stations are equipped with wireless network interface cards (WNICs). Stations fall into one of two categories:

Wireless Clients and

Access Points.

Access Points (APs)

Access Points are base stations for the wireless network. They transmit and receive radio frequencies for wireless enabled devices to communicate with.

Wireless Clients

Wireless clients can be mobile devices such as laptops, personal digital assistants (PDAs), IP phones or fixed devices such as desktops and workstations that are equipped with a wireless network interface card.

REMOTE ACCESS

Perhaps you want to work form home once a week, but still want to access files on a PC in the office. This can be achieved efficiently and cost effectively. One of the PC's in the office needs a phone line linking into it. You dial through your home phone line directly into that PC and the two modems establish a connection. Once connected, you have full access to all the other PC's and hardware in the office network.

VIRTUAL PRIVATE NETWORK

Perhaps your sales team is geographically dispersed and need regular access to the company network to process orders and check stock status.

A Virtual Private Network (VPN) may utilise your existing network and public networks such as the Internet . For example a sales representative based in the UK can Telework from their hotel by dialling in over the Internet to the office network in Ireland, and work away as if the user was in the company office. With the remote connection established, the user has access to everything that is normally available when sitting at the desk.

To set up a VPN, additional software, hardware and security is required. However, the savings in the long term could far outweigh the initial costs that are incurred. For example, a UK based employee accesses the VPN by making a local call to an ISP and through that Internet connection he can access the company office network and other relevant company information. Because the UK employee is using a VPN over the Internet , the cost of the connection is a local call to the ISP instead of an international call to the head office. Multiply this scenario and the savings soon become apparent.

4. THE INTERNET

The Internet is a computer network made up of thousands of networks worldwide. No one knows exactly how many computers are connected to the Internet . It is certain, however, that these number in the millions.

No one is in charge of the Internet . There are organisations which develop technical aspects of this network and set standards for creating applications on it, but no governing body is in control. The Internet backbone, through which Internet traffic flows, is owned by private companies.

All computers on the Internet communicate with one another using a standard or protocol called the Transmission Control Protocol/Internet Protocol suite, abbreviated to TCP/IP. Computers on the Internet use a client/server architecture. This means that the remote machine (server) provides files and services to the user's local (client) machine.

Internet and World Wide Web
Often the terms Internet and web are used synonymously. In casual conversation such as 'I was on the Internet ' or 'I was on the Web,' there is no difference. However in practice these are two entirely different items. In the same way that a car travels on a road, a web page travels over the Internet, which is the physical network. An Internet user has access to a wide variety of services: electronic mail, file transfer, vast information resources, interest group membership, interactive groups, multimedia displays, real-time (live) broadcasting, shopping opportunities, breaking news, and much more.

The World Wide Web is basically a particular way of transporting text, images (graphics) and other multimedia content e.g. video and sound clips, over the Internet .

Web servers (computers or software) on the Internet are set to respond to particular requests by sending documents to the requester, usually done in HTML.

HTML stand for Hyper Text Mark up Language and it is a standard language made for typesetting. It is mainly used for creating documents on the World Wide Web. Included in the language are provisions for including pictures and links to other pages. The requester must use a browser (software programme) to receive this data.

5. EMAIL 

Email stands for electronic mail. Email is the most commonly used application on the Internet . Email allows you to send text messages across a network, either an internal network or an external one like the Internet .

To send an email you must know the email address of the person you want to send the mail to e.g. john@somewhere.com.

An email address is comprised of a user name, in this case john, and the name of the server that the mail has been sent to, in this case somewhere.com.. The power of email can be seen from the fact that traditional paper-based mailing list procedures are now being superseded by mail-shots at targeted audiences, which can be transmitted instantly at little cost via electronic mail.

Emailing [external] people requires a computer with Internet access. Specialist software packages facilitate the delivery and receipt of email. There are two ways to receive email;

via specialist programmes or software package

via a web service e.g. Hotmail or yahoo! Web-based email is typically free.

Email Software Package

If you use a software package such as Outlook Express or Eudora, they are far richer in features than web service email facilities. This software will be configured (set up) to use your chosen Internet Service Provider's (ISP) service and will dial to in to this service to receive and send your emails. One of the advantages of using an email package on your PC is that you can control various limits, for example with free email you typically do not get a very large mailbox and your mailbox can fill up - if you do not routinely check your mail subsequent emails and attachments will be turned away. With your own email software, you will typically have much higher size limits and more control over managing the process. Most business people use computer-based software such as Microsoft Outlook, or Lotus Notes.

Email has many benefits including speed, the fact that you can send 'attachments' (e.g. documents) with your email and the fact that the physical location of the sender or recipient is immaterial to the activity.

6. WEBSITES A website is a location on the Web owned and controlled by a single person or organisation. It is a set of HTML pages linked to each other. Initially company websites simply reflected their corporate brochures and although this is still the case for some business sites, others are using websites to transact business, allow customers access to their account information, allow suppliers access to company systems, allow purchasers to check quotes across a variety of suppliers and many more applications.

To have a website available to the Internet 24 hours a day 365 days a year your web server needs to be connected to the Internet permanently. This permanent connection used to be costly however costs have reduced significantly in recent years. However this does raise other issues such as security and reliability. Typically a company will use an Internet service provider (ISP) or hosting company who will store the company website on hi-spec web servers (machines) and make the website available twenty four hours a day, seven days a week.

7. BROWSERS

A browser is a program that allows your computer to access and display web pages. It interprets the electronic information from the Internet, and allows you control what pages you view.

Many different browsers are available, but the most popular of them are Microsoft Internet Explorer and Netscape Navigator. It's important to make sure that you always have the most recent edition, as new features are added all the time. Updates are free and will help you enjoy the latest developments which web designers are using on sites e.g. dynamic images.

8. SEARCH ENGINES AND DIRECTORIES

Search Engines

Search engines are tools which enable people to search the Internets pages for specific information or websites. Simply type one or more words into the search box and click on the search button. A list of matching web pages will be displayed. So click on one to visit it.

When it comes to search engines, Google is among the most popular, accessing information on such wide-ranging subjects as careers, shopping, auctions, film and movie reviews, free email, etc.

Directories

Directories perform a similar task to search engines in that they hunt for information on web sites, but they differ in one important respect. Directories are hierarchical lists of information which need a level of refinement not required with search engines. Among the most popular directories is Yahoo!

Some companies have found it cost effective to pay specialist vendors to ensure that the company web site always features very well when a potential customer does a search on the Internet. However, before paying another vendor to improve the visibility on the web, an astute company with knowledge of how search engines work on the web could do many things to improve web visibility. This all comes under the umbrella of 'Search Engine Optimisation' and is an area that is now receiving a lot of coverage in books on e-Business and on the Internet .

9. SECURITY

Information Technology can give companies a competitive advantage. However, this can mean that customers, suppliers, contractors, and business partners are routinely allowed access to critical business data and to the systems that process and store the information. Consequently, companies must have a security program.

The three fundamentals of a security program are

Confidentiality -- only authorised parties can read the details of the transaction

Integrity -- unauthorised modifications of the transaction will be detected

Availability -- systems are reliable and recoverable

There are many areas that a company may address as part of a security program and these include:

Regular Backups and Recovery;

Anti Virus Protection;

Disaster Recovery;

Audit Logs and Monitoring of unusual activity

Authorised User Access utilising password control.