You can get the version number of the repo package using
apt-cache policy skype
For my 14.04.2 setup, this returns:
skype:
Installed: (none)
Candidate: 4.3.0.37-0ubuntu0.12.04.1
Version table:
4.3.0.37-0ubuntu0.12.04.1 0
500 http://archive.canonical.com/ubuntu/ trusty/partner amd64 Packages
So the version in the Trusty repos is 4.3.0.37-0. The package downloaded from Skype's website is named
skype-ubuntu-precise_4.3.0.37-1_i386.deb
So it has version 4.3.0.37-1.
The number after the hyphen usually indicates a change in the packaging, not in the software itself.
The fact that the package is called ubuntu-precise
means that it was packaged for 12.04 Precise Pangolin. So one can see that the software hasn't undergone any change in the past two years (or that the devs were too lazy to update the version number in the package control file...)
So eventually both packages ship with the same version of Skype. If you, however, compare apt-cache show skype
with the DEBIAN/control
file of the package from the website, you'll see that the packages are maintained by different people. Still, the software is the same.