Windows 7: What is C:\Users\PC\AppData\Local\Temp ? :)

While i was exploring windows explorer, i came up to this folder C:\Users\PC\AppData\Local\Temp



What does it contain?
What are tmp, old, mtx, and text document files?
Is it ok to delete this folder? (I don't know what came up to my mind, i just feel i want to delete some stuff on my computer xD )
Some files and folders that are 0kb in size , how did they came up to the folder?
can i delete those 0kb files?

*actually i don't know where to post this question so i just put it in General Discussion

Temp = Temporary. Sure you can deduce the purpose now.

If you want to get rid of accumulated junk on your computer, install CCleaner. Run just the Cleaner part. Uncheck any areas you don't want deleted, like Cookies, History, Recently Types URLs, etc.

It will empty the AppData\Local\Temp area and many others as well.

This is how I have mine setup:

The safe way to do it from Windows is to just run disk cleanup.
Disk Cleanup - Open and Use
EDIT: I'm not 100% sure the above cleans out that particular folder but running Disk Cleanup is a good place to start anyway.

I'm sure, as mine is empty and I don't use Disk Cleanup.