Full version vs Lite Version
The Lite version is stripped down to create a smaller image (needed for the compute module fixed 4GB flash memory for instance) and doesn't include the GUI (command line use only).
Jessie vs Wheezy
Official posts about the change
Raspbian has been updated to the new stable version of Debian, which is called Jessie.
Boots straight to desktop instead of the command line. Can be changed back using the Raspberry Pi Configuration application.