SOFTWARE

Software is another name for the programs that run on a computer.

A program is a series of computer instructions which tells the computer what to do.

There are two (2) main categories of software:

1. Application Software                                 2. Systems Software

APPLICATION SOFTWARE

Application software is defined as programs that enable the computer to carry out one or more specific tasks.

Types of Application Software

1. General-purpose software – also known as ‘off the shelf’ software. This is the most popular application programs that are used by organizations, businesses, schools and by individuals at home.  Examples include Microsoft Office, Games, Math Tutor, Typing Tutor etc.

These programs are called general-purpose because the user decides what to use the software for, e.g. word processing software can be used to write letters, reports and memos, databases can be used for searching and sorting data etc.

Generally much cheaper since it used by millions of people around the world and they are generally error (bug) free.

2. Custom-written software – also known as ‘tailor-made’.  This is software written to meet the specific needs of a company.  It may be written by individuals within the company or contracted out to a software house (a company that specializes in writing software).  This may be necessary because there are no commercial applications available.  Custom written software is very expensive.

3. Specialized software – this is written solely for a specific task.  Examples are software used by air traffic controllers to manage the flights of thousands of aircrafts, accounting software, airline reservations etc.

These are not general-purpose since the users of these kinds of software (for example accountants and engineers) are trained in a particular field of expertise.  Since this software is specific to an organisation or business, it can be very costly to create.

4. Integrated software – this is a term used to describe a program that includes the major types of applications such as word processing, spreadsheets, database, presentation programs etc. and brings them together into a single software package, for example Microsoft Office Professional 2007. A major advantage of these packages is the ease with which data can be transferred from one component to another (via copy, paste, import etc.).

SYSTEMS SOFTWARE

The operating system and utility programs are the two major categories of system software.

Utility Programs

Utility programs help manage, maintain and control computer resources. These programs are available to help you with the day-to-day chores associated with personal computing and to keep your system running at peak performance. 

Some examples of utility programs include:

ü  Virus scanning software

ü  Backup software

ü  Scandisk

ü  Disk defragmenter

Virus Scanning Software (Anti-virus software) is a utility program designed to protect your computer from computer viruses. Virus scanning software is critical due to the number of computer viruses. Updates insure that your virus scanning software will protect you from the most recent viruses. Virus scanning packages come with directions on how to receive updates to your software!

Backup software is software that assists you in backing up your files, including the entire computer hard disk. It is important for you to back up your files regularly because in the event of computer failure, all necessary data will be saved to another storage medium.

Scandisk is a utility provided with Windows computers. Scandisk scans your disks to see if there are any potential problems on the disk, such as bad disk areas. Since disks are magnetic media, all disks, including your hard disk can be corrupted.

Disk Defragmenter software assists you in reorganizing your disk drives. After files are saved, deleted and re-saved again, the disk can become fragmented --- available space is in small blocks located throughout the disk. Disk defragmenters gather those free spots and put them together to enable you to continue to save your data in the most efficient manner.

Operating Systems (O.S.)

An operating system is a set of programs that govern the operation of a computer. 

Without operating system software, the computer would not be able to function.  Therefore, the O.S. is switched on as soon as the computer is power on or ‘boot’ the system.

Booting is the process of loading the operating system software into a computer’s main memory from disk.

Types of Operating Systems

The older O.S. used by computers is DOS (Disk Operating System) which uses a command-line interface. Commands were typed into the machine using the keyboard rather than using a mouse to select an object on the screen. The system then read this command and carried it out.

Microsoft Windows (e.g. Windows 98, Windows XP, Windows Vista) and Apple Macintosh OS are also operating systems.  They provide a picture-based interface called a graphical user interface or GUI.  With a GUI, you often use a mouse to select the operations you want to perform.  Other OS include Linux and Unix.

Functions of the Operating System

1. File management – performs functions such as saving, copying, renaming erasing, deleting and backing-up files.

2. Memory management – the OS manages all the files on a computer.  It keeps track of the locations where programs and data are stored within the computer’s memory. 

3. Security – allows the user to set passwords to allow only those users with the correct password to use the system.  The OS keeps a log which records users logged in, the length of time each user spent on the system and what they did.  Administrators can check the log to look for security breaches and abuse of resources.

4. Device management – the OS sets rules for controlling hardware resources such as:

ü  Peripherals – controlling devices such as keyboards, printers and scanners.

ü  Memory – controlling the amount of memory used

ü  CPU – controlling the time allocated to a task by the CPU

ü  Disk space – controlling the amount of disk space used

5. Managing computer resources – the OS allows application software such word processors, spreadsheets and database packages to communicate with the computer’s hardware.  For example printing a document.

6. Managing tasks – a computer can perform many tasks simultaneously.  One way of doing this is by multi-tasking, i.e. the ability of a computer to run more than one program at the same time.  For example, a user can listen to music while typing a document or playing a computer game.

In the case of networks, multi-user OS allows more than one user to access the same data at the same time.