Capacitive: Generally more expensive, can support "multi-touch", rely on skin contact because the persons electrical field is what causes changes. This means they don't work well, or at all with gloves on. Doesn't rely on touch pressure, so are generally more responsive to finger use/light taps, etc. Requires a fairly complicated controller.
Resistive: Cheap, only a single touch point can be detected. Rely on pressure to achieve detection (u may have to push hard on them). Any object touching the screen can create a "press" event, so gloves, non-conductive pens, etc work fine. Controller is very simple, just measures a few resistances.