There are many types of Golf Analyzers out there...
Systems like the Optishot, P3ProSwing measure what your club is doing. They measure analytics such as swing path, face angle, club head speed and more. From these analytics, calculations on ball flight can be made and shown on a computer screen or projected onto an impact screen for full simulation.
Here is where it gets complicated. There are systems out there like AccuSport, Foresight Sports, Full Swing Golf and more that measure different aspects of the ball such as spin, velocity and most importantly launch angle. The complicated part is that some measure all and some only minor and they can be difficult to setup. These systems are great for clubfitting and can be great for basic golf simulation. The launch angle and spin can really help you hone in on your game if you are a low handicap golfer.
Club & Ball Analysis:
Some systems like the Golf Achiever, GolfTek, Sports Coach, About Golf and others can measure both the club and the ball. These systems give you the benefits of both analytics, but tend to be more expensive than the others. Sports Coach's new 3D High Speed Camera system is really cool, as it allows you to hit off of almost any surface, is easy to setup and only costs about $11k for the cameras and software. This may still be a little high for most golfers who just want to improve at home.
There are really simple software systems that work off of basic web cameras and there are complex ones that rely on high quality video cameras. The software can then be as basic as showing your swing, others that you can draw lines on and even ones that you can overlay your swing on top of pros like Tiger Woods. I am not an expert in this field but if you Google it, you can find some great systems out there. PS the P3Pro includes a video capture option for up to two cameras at once (this makes it a great learning tool as you can combine it with the analytics and simulation all on one screen!)
Systems such as the K-Vest measure what your body is doing - a very cool concept but not something most people can afford for their home. Some pro shops and instructors will offer this to their clients to get even further analysis on what the golfer's body is doing. There is also plate analytics to measure the weight variations between your feet as your body moves during the swing.
OK, so that seems like a long winded explanation, but it really just scratches the surface. If you want more information or need help finding a system that is right for you, feel free to contact me.
Keep Your Eye on the Ball,
Cory Gauvreau, Par2Pro