Difference between .Deb and .tar Packages

[Jatin Davey]

Hi all

I would like to know the difference between the .Deb Packages and .tar 
Packages.

Why i am asking this question ?
    -- Because most of the software applications that i intend to 
install come either in .Deb packages or .tar files.

Do all the .Deb package or the .tar package include all the dependencies 
that the package requires to run properly ?

Thanks
Jatin