There is no standard File-Extention like an ".exe" file in Windows.

On Linux nearly any file can be executable.
The file ending just describes (but not necessarily) what or how a file is "executed".

For example a shell script ends with .sh and is "executed" via the bash shell.

In your question you ask for .deb and .tar.gz
Well, the .deb file installs software on your system (Please be careful!)
And the .tar.gz file is a compressed file like a .zip that you could know from Windows.