Apologies if this has already been answered, but I was thinking a sticky describing the basic types of motors, how they work and what they are typically used for would be really helpful.
I am about to embark on my first mechatronic project and am unsure which type of motor I need. I just bought the Freetronic experimenters kit and it has a servo, so I know servos have a little board in them that controls the motor movement - coz I can see it.
I want to hold something in position (like a camera pan and tilt assembly). I'd like a continuous 360 degree pan. I also wanted a continuous 360 degree tilt, but am prepared to compromise to a fixed 360 degree tilt if I can go 180 degrees in either direction.
When tilted, I want it held in position. I also want the pan to remain steady. Do I use a servo? A stepper? Can I just use a standard motor? I have looked at the servo city camera pan+tilt units, so I can get an idea of how they work and what they use - but is that the only way to do it? And when they have multiple options, which one suits my application? And good grief that stuff is expensive - can I do it cheaper by using a different motor if the weight of what I want to hold steady and the expected load it has to resist is low?
In my head I don't know how the different motors work, either. If I have just tilted to 45 degrees - does the motor stay "on" to hold it in that position (I am guessing yes), or does internal gear friction hold it there (thinking about it that seems silly, so I am guessing no). Whereas I can see with a worm drive if I have panned to a position, it's possible I can turn the motor off now, as the internal gearing and worm gear mechanism provide resistance - but that's again, just a guess.
I would LOVE to go to a shop and just play with all these different things so I could handle them and see them in operation. If ServoCity would open up a "come n try" shop here in Melbourne I'd spend the next month there 24/7!! 
Not aware of any such shop though, so in the mean time, some basic, quick reference info would be very handy.
A table listing things like:
Motor type
Typically powered / controlled by (microcomputer / self / external motor driver circuit)
Basic operation (PWM, +/- DC, constant power applied by circuit / move motor then switch off)
Typical uses
Typical range of motion
Typical load type: dynamic / static, heavy / light, horizontal / vertical.
etc (?)
would be handy, as well as some of the more common gotchas / terms, like:
backlash - what it is, how each motor or system handles it, how to negate it
flyback voltage - what it is, how each motor handles it, how to negate it
etc (?)
I am obviously learning some of these things, but it's taking a lot of reading and trawling through forums and threads to glean the basics.
Thoughts?