RAM - Random Access Memory. Its the temporary storage of all running programs or ultilities you will be running in your computer.The amount of RAM your memory card contains will tell you how fast your computer will operate. Its like this. lets say you're playing a game in your computer which requires at least 100mb of RAM to run and your computer only has 256 mb of RAM?? Your game will still run but it will not still run smoothly because aside from the 100mb of RAM the game will be using, you still have other programs or components you will be running like MSPaint, Internet Explorer which will add to the 100mb your game requires.

lets say

100mb for game + 50 for another program + 50for another program = 200mb of ram. So you will only have 56mb remaining(56 is too low)

If you only have 256mb ram of memory card and your run all those three at the same time(make it active), you might experience your system to hang or pause because the remaining mb of ram will be very low.

I suggest that you buy a computer with 1gb or 2gb ram of memory.

And find a computer which has better graphics. At least 256mb ram of video card or 512mb for video card if you want(its more expensive)

Try to check also how much Ghz(Gigaheartz) your computer has. Buy something which has at least 3.0ghz. It will surely work fast.

and lastly buy a computer which has at least 40-100gb of hard disk drive for your storage.

Good Luck!