if u mean that u can use pwm pins as power suply the anwser is: depending on the current-draw of the motor, yes (btw there is no max-Voltage differnce between digital and pwm..)
the arduino i/o pins can output max 40 mA. for example: if the motor is drawing 200mA u will need to connect the motor serpartly to a power source, than use a transistor like mentionted by johnwasser.
lots of these stuff is also all around the net (hint: google)
just search and you will find, when u still dont understand something its worth posting.
nick