Applications and programming languagesDoor Ethan Moye
1. Graphical user interfaces Graphical user interface is sometimes shortened to GUI. The user chooses an option usually by pointing a mouse at an icon representing that option. Features of GUIs include: They are much easier to use for beginners. They enable you to easily exchange information between software using cut and paste or 'drag and drop'. They use a lot of memory and processing power. It can be slower to use than a command-line interface if you are an expert user. They can be irritating to experienced users when simple tasks require a number of operations. When discussing user interfaces, it is important to note that Windows XP, Windows Vista, Apple OSX and Ubuntu all have graphical user interfaces. Good user interfaces A good user interface should: be attractive and pleasing to the eye allow the user to try out different options easily be easy to use use suitable colours for key areas use words that are easy to understand aimed at the type of user have help documentation It should also consider the needs of the users. For example, young children are likely to prefer pictures to words and people with disabilities may benefit from particular input or output devices.
2. Simple menu The user is offered a simple menu from which to choose an option. One menu often leads to a further menu. Part of the screen may have an instruction followed by a numbered list of options to choose from. Full screen menu A full screen menu takes up the entire screen. Menu bar A menu bar is the set of options at the top of the screen. When an option is chosen a drop-down menu may be offered. Features of menu driven interfaces include: they are easy to use as the user does not have to remember sets of commands they are user friendly - you can often guess your way around the options they can be irritating if there are too many levels of menus to move around - with a command-line interface you can go to the option required immediately
3. Command-line interfaces A command-line interface allows the user to interact with the computer by typing in commands. The computer displays a prompt, the user keys in the command and presses enter or return. Person using command line on a laptop beside a person using a typical user interface In the early days of personal computers, all PCs used command-line interfaces. Features of a command-line interface Commands must be typed correctly and in the right order or the command will not work. Experienced users who know the commands can work very quickly without having to find their way around menus. An advantage of command driven programs is that they do not need the memory and processing power of the latest computer and will often run on lower spec machines. Command driven programs do not need to run in Windows. A command-line interface can run many programs, for example a batch file could launch half a dozen programs to do its task. An inexperienced user can sometimes find a command driven program difficult to use because of the number of commands that have to be learnt. An example of a common command driven interface is MS-DOS. The MS-DOS command to display all files on c:\ would be: dir c:\
4. User interfaces
5. Menu driven interfaces
6. Graphical user interfaces
7. A programming language is a specially written code used for writing applications. C++ and Java are examples of programming languages. These are known as high level languages because they have been developed to be a little like a human language. High level languages are much easier to use than a low level language such as machine code, or assembly language. The advantage of a low level language is that it runs very fast on the computer.
8. Applications come in several different types: Utility programs - examples include virus scanners, disk defragmenters and backup utilities. Generic - general purpose software that is not written for any particular type of business. Examples of this include word processors and spreadsheets. Integrated - a collection of software that has a common set of commands/icons. Usually they include word processors, spreadsheets and graphics software, but they can contain databases as well. They tend to be cheaper than purchasing each application separately. Specific - software written for a defined purpose. Accountancy software is a good example of this that can be bought by anyone. Bespoke - bespoke software is written when a company requires a piece of software to perform a very specific task or function and there's no existing software that does what they need. It can be very expensive.
