RS232 versus TTL, for cameras?

I've been noticing that some of those barebones miniature cameras suitable for usage for robotic vision come in two flavors. One flavor supports RS232, and the other flavor supports TTL.

I know what RS232 is, but what is TTL?

Is it this? http://en.wikipedia.org/wiki/Transistor-transistor_logic

I'm (or at least, used to be) familiar with working with RS232. Does anyone have any pointer to working with TTL?

 

Robot brain level

TTL is robot brain level. The inputs and output to a typical microcontroller are at TTL level, usually 3.3v or 5v.

More of a question than an answer, but,

I wonder if TTL vs RS232 is being listed because RS232 is inverted logic as well as being different voltages like Chris mentioned; TTL = 5v or 3.3v and RS232 = 12+/- v.