Mecha can be used to describe any race that's walking around and was created by someone else out of inorganic parts. This not only includes robots of all shapes and sizes, but also golems, which are magically-created constructs. Many of them were created with programmed personalities, but in MSF High they've got free will of their own and have managed to break free of their programming limitations. This actually happens quite a bit in the rest of the galaxy as well, and the CTS is known for harboring good rogue AIs. Many mecha, however, were crafted out of love and remain loyal to their creators. It's also worthy of note that a number of students have created mecha on their own, and while not an actual birth, many of the mechas' awakenings are celebrated in much the same manner.
Powers
Absorb: Mechas' bodies are designed with magic in mind, and can take a hit better than most races. In fact, as they grow stronger, they're able to convert more magic damage per day into energy that can power their self-repair systems or spells of their own. If you're fighting one with magic and strength, it may be a good idea to hit them with enough magic to use up their absorb power before you start hacking away at them. Not that getting up close and personal's that good an idea either.
User-Friendly: Mechas work well with other races, especially Humans. They gain a bonus when trying to work together with non-mecha, and the bonus stacks with the humans' tech bonus.
Race Stats: