Software

The software on the computer is the programs on the computer. A computer program is a list of instructions that the computer performs. Programs tell the computer what to do. Without a program, a computer can not do anything.

Computer programs are written in a programming language. This language is then compiled (checked for errors) and translated into the binary code the computer understands.

Example of a Computer Program

Computer software (programs) are divided into two main categories. There are operating system programs and application programs.

Operating systems are programs like Dos and OS/8. They let you tell the computer where to save your files, what application programs to run, what files to delete etc.

Application Programs are programs that let you do things on the computer. They include (but are not limited to) word processors, spreadsheets, databases, graphics programs, and games.

Operating Systems

These are programs that provide a link between the computer's hardware and the application program(s) it is running. The operating system manages the computer's hardware resources eg memory.

When the computer is turned on , the operating system is loaded into RAM from disk (usually the hard disk) or from ROM. This is called booting the system.

The operating system is what makes it possible for you to read files from a disk, save files to a disk, copy files, delete files, run application programs etc. Without an operating system, your computer will not work.

Different computers use different operating systems. Different programs require different operating systems to work. For example, a program written to work with the Apple Macintosh OS/8 will not work with the Windows 95 operating system.

The trend today is for operating systems to be GUIs - graphical user interfaces. This means that to use them you click on icons (pictures) and pull down menus. This is a lot easier than remembering the long lines of code required in earlier operating systems eg DOS

Application programs

Application programs are programs that let you do things on the computer. Word Processing, Spreadsheet and Database programs are three common types of application programs.

Application programs of different types can be put together into one large program.. This is called an Integrated Software Package. These give you four or five different application programs in one group. Examples of integrated software packages are Microsoft Office and Claris 5.0.

There can be many individual programs under one type of application program. For example, word processing programs include Microsoft Word 6, Microsoft Word 97, WordPerfect 5.0, etc.

For most application programs, the cursor appears as a flashing bar on your screen. When you type, the text appears where the cursor is.

The cursor is not the same as the mouse pointer, which appears as an arrow or as an I-beam. You can move the cursor around the screen by clicking with the mouse pointer. The cursor will move to where you have clicked.

Word Processors

Word processing programs are the most commonly used application programs. The purpose of a word processor is to allow people to write. Once a document is created, it can be edited and formatted without labouriously re-typing the document each time. Word processors make it a lot easier to edit your text. They offer a large variety of print styles. The document is stored easily on disk and can be retrieved and used easily.

Many word processors display the document on the screen as close as possible to how it will look when it is printed out. This is called WYSIWYG (what you see is what you get).

Most word processors also use word wrap. When you are typing and you reach the end of a line, the computer will automatically put the text on the next line. When you take text out, the computer automatically closes the gap. This is also called using a soft return.

A hard return is when you press enter at the end of a line. This is usually used only to create paragraphs. Putting a hard return at the end of every line invalidates the word wrap function and makes editing your text very difficult.

Spreadsheets

Spreadsheet programs organise and store data that you want to use in mathematical calculations. They perform calculations quickly and easily. If one number is changed the entire spreadsheet can be recalculated for you.

Spreadsheets are divided into rows and columns. Rows are usually numbered while columns are given alphabetical references. The intersection of a row and a column is called a cell.

An item of data on a spreadsheet is entered into a cell.

Databases

Database programs organise and store data.

They are divided into files, records and fields. Fields are a division off a record eg a persons name, address or phone number. A record is all fields for one specific entry eg one person. A file is all the information on one particular subject eg peoples addresses. A database is made up of one or more files.

Databases can be searched to quickly find the information or data required by the user. They can be sorted on relevant fields eg last name. A database report can be printed showing only relevant records and fields.