Quick iTunes question

So I'm staying with some family right now for Christmas and I just got a Ipod touch. I've downloaded iTunes onto their computer, and want to buy a few things, but I'm afraid that if I do then when I download iTunes onto my home computer that it will erase whatever I buy. So pretty much I want to know if things purchased on iTunes are locked to the computer they are purchased on or the account they are purchased on. Thanks in advance,

Nails

You can download songs purchased through itunes on up to 5 computers.

does this apply to games apps and movies too?

I know you can play music you've purchased on up to five computers... but I don't think you can re-download. You have to copy the files to your home computer manually.

"does this apply to games apps and movies too?"

Only bought suff though, if your fingers slip, and you happen to get some stuff illegally, that won't transfer over.

You have to authorize your other computers. It will ask for a name and password, and give it your apple ID on your other computer to play those items.