which file type is the best? jpg,png,gif etc.

so which is the best to use?

people keep asking me to save it in .png format...why so? is it better?

hmm i use png cuz i think it has better depth. looks better as png to me

This has already been addressed. There are various reasons for each codec, and those can be googled.

Yes, this already has been posted before, use the search function please.