An auto tech is one that does work on vehicles, their engine, diagnostic work, and other problems are car might have run in to. Depending on the type of tech, and whether or not they have specialty training, there are also other jobs that they might be entrusted with, depending on the employer. In many shops and repair shops, a tech is going to usually specialize in a certain area of repair; but, depending on the size of the shop, and the number of techs, many are going to take on more than one task, and more than one job, in the position that they hold.
When deciding to become a tech, if possible, you should consider getting some kind of specialty training. Not only are you going to be more of an asset to a repair shop, you are going to be able to do more work, do more than one task, and you are likely going to earn a higher pay rate as well, due to the fact that you have more to offer to the repair shop. So, when you are training, and getting certified to become a tech, if possible, consider some type of specialty training, as well as the basic training, so you can offer more to an employer once you are done with your training.
The more skills and qualifications you have, and the more specialized you are, the more you can expect to earn, when you do apply for jobs with local body and repair shops. As a tech, you are going to learn there are quite a few positions you can take on, so the more you can learn along the way, and the more training you can get, the easier it will be for you to find the higher paying jobs.