Now, What's The Difference From A Television Sitcom And A Comedy Drama?

A comedy drama differs from a sitcom if it features most of the following attributes.

1/ Drama directs the plot not the comedy.
2/ Tragicomedy, whereby the comedy often acts as a light relief to the drama
3/ The absence of a live studio audience or a laughter track
4/ Usually longer episode's than a sitcom, an hour to 45 minutes rather than 30 - 25 minutes
5/ The shop's narrative doesn't have to takes place in a specific or unusual 'situation'
6/ Events follow up throughout the series and are alluded to in future episodes

Some sitcoms and comedy drama's share attributes from both, however usually the show will have a particular feel of either a sitcom or a comedy drama.  Here's a list of Comedy Drama's past and present:

Ally Macbeal
At Home With The Braithwaite's
Auf Wiedersehen, Pet
Clocking Off
Cold Feet
Curb Your Enthusiasm
Extras
Gavin And Stacey
Just Good Friends
Last Tango In Halifax
Linda Green
The Office
Outnumbered
Parks And Recreation
Peep Show
Sex And The City
Shameless
Teachers
This Life
Ugly Betty