Backup – re-add? re-installation?

Hey. I recently had my server delete all my stuff, but was able to svae my wp back up.
I have downloaded the wp zip file. But it’s asking me what the file type is in side the zip file.
I don’t have a clue! Can anyone tell me?
It says .doc is a common one. I tried that, and it came up all messy – but it did contain my posts.
Someone please help me!