For people who has been using and working with computers for years, it can be easy to forget that there are many other people who do not know what some relatively common terms mean, such as desktops, laptops, hardware and software. As a result I've written this short guide to explain what these four common terms mean.

Desktop Computers are – as their name suggests – computer systems which are designed to be put and used on a desk, or at least a single location (i.e. they aren't designed to be portable). Whilst this might sound simple, when computers were first designed they were the size of a small room! And as a result, computers which were able to fit on a desk were seen as a very big technological breakthrough.

Desktops have multiple parts: there is a case which houses the various electrical components ('hardware') which makes the computer run, then there's usually at least a monitor (the display device which we look at when using a computer), a speaker (to output sounds and music), a mouse (to control the on-screen cursor) and a keyword (used to input information into a computer). These four devices all plug-in to the computer case. Desktop computers are also commonly called 'desktops' or sometimes simply as 'computers'.

Laptop Computers are smaller than desktops. This is because they are designed to be portable; in other words, so that they can be easily carried around by someone. Laptops were originally intended to be usable on someone's lap (naturally this is where their name comes from!). However due to the large heat that laptop computers generate, this is discouraged. The various parts of a desktop computer (a monitor/display device, keyboard) are all integrated into a laptop.

To help with portability, laptops can be powered via a rechargeable battery or off mains electricity. When connected to mains power, the laptop's battery recharges. And when used without mains power, the laptop uses the battery's power to run. A typical laptop can run for 3-5 hours on batter power.

Hardware ('Computer Parts') is the term used to be describe the various electrical components inside a computer which make it work. A typical computing device (for example a desktop, laptop or even a mobile phone) tends to have as many as ten hardware components inside it. For example – speaking in rough terms – a 'hard-drive' is the component which stores data, a 'CPU' performs calculations, and a 'motherboard' houses these various components.

Software Programs are the computer programs which allow you to perform certain actions and tasks on a computer. There are two broad types of software: application software and operating system software.

Operating system software is a large, complex piece of software which manages every single aspect of a computer – for example, it manages the computer's hardware, the way users interact with a computer, the application software installed on the system, and more. Examples of an operating system include Windows XP, Windows 7 and Linux.

Application software - on the other hard – is a usually smaller and less complex piece of software which performs certain actions. For example, digital photo editing software is application software which allows you to modify photographs in various ways (for example, color correction, red eye removal, cropping, and more).