If you're thinking of buying a digital camera then you need to look at its size, the quality of the pictures you'll get, the number of pics it can store and how fast you can copy them to your PC, its battery life and - of course - the cost.

This is a long list, but you need to be sure that you're buying a camera that will do all the things you want.

You wouldn't want to buy the first camera you saw only to find there are cheaper models around that do everything you want.

What sort of photo

Ask yourself what sort of photos you're likely to take - will they mostly be holiday snaps or quick photos of the kids playing in the park?

Or do you want everyone in their best clothes with hair brushed and mouths wiped for the family portrait?

Do you want to carry the camera with you everywhere or does it only come out on special occasions?

If you only take the occasional photo then a cheaper, bigger camera might be all you need, but if you take it everywhere and want lots of pics you'll have to spend more for a pocket camera - one that's smaller and can hold lots of shots.

A professional model will be bigger and even more costly, just because it does so much.

How many dots

A cheap digital camera will take photos that look fine if you look at them on screen, send them via e-mail or put them onto a website, but they won't print out very well.

That's because every picture you take is made up of lots of coloured dots, called 'pixels'.

Look really closely at any of the pics on this page and you'll see them. The more dots, the better the picture looks - but each dot takes up some computer memory.