There are many factors into deciding which bulb to put into your lighting fixture. The easiest place to start when looking, is with the base of the bulb, Do you need a screw in base or a T-Pin Style base, otherwise known as GU24, or Medium Base Sockets?
The GU24 is a t-pin socket, usually containing two pins at the bottom that you line up with the base of the lighting fixture, twist, and then click into place. The Medium Base Socket, or Edison Screw, is threaded so a simple screw motion is required to get one in place.
Both the Medium Base Socket and GU24 have the capabilities to be C.F.L’s (Compact Fluorescent Lamp) and the bases don’t affect whether or not the style of bulb is LED, or what color temperature they produce. The color temperature for GU24 ranges form 2700 Kelvin to 5000 Kelvin, and Medium Base bulbs ranging from 2700 Kelvin and to 6000 Kelvin.
Other factors that go into buying a bulb are, color temperature, wattage, and how energy efficient your bulb is. The best way to get the most energy efficient bulb, along many other benefits, is to look at the LED options.