what is a .cab?

[reyrey127]

Here is a NOOBILICIOUS question..

What is a .cab?? I mean I have seen a lot of .cab files being talked about, like Spbackup.cab, etc. If i want a .cab and it is zipped, and i saved it to my PC, and unzipped it, what do i do with that. cab file. Can I just copy it to my storage card? If I do, how do i install it or get access to it through the phone??

For example, I want to download a .cab that backsup my contacts and documents. How do I install the .cab??

Thanks.