When I run
apt-cache show gedit
I see, among other things,

Installed-Size: 2699
and further down, there is:
Size: 532268

I figure that the former is in kB and represents the size after installation while the latter is in bytes and is the size of the download.
My question is this: Is the latter size the same that gedit would take up on the .iso or are packages on the .iso compressed differently?