Here is a brief description of the most common axle design:

Drive/CV Axle:

Simply put, a drive axle is one that is driven by the engine. Typically found in modern front wheel drive vehicles, a drive axle is split between two half axles, with differential and universal joints between them. Each half axle is connected to the wheel by a third joint—the constant velocity (CV) joint—that allows the wheels to move freely. This joint allows the shaft to rotate, transmitting power at a constant speed without a significant increase in friction and heat. CV joints are usually dependable, but, as is the case for all of your vehicle's moving equipment, they do require regular inspection. An easy way for you to tell if you need to see us for axle repair is to go out to a large space (such as a parking lot), and slowly drive in tight circles. If you hear a clicking or cracking noise, you have a worn joint, and it must be repaired immediately.