Some dildos are also vibrators, but don't let that confuse you, because not all vibrators are dildos.
More specifically, dildos are objects, often phallic in design, that are designed to penetrate whatever orifice you fancy. A few have the added feature of a vibrating bullet or similar device, but most are just made for screwing.
Vibrators are much more specialized tools, some of which are meant for internal stimulation (g-spot or p-spot), and some outside (clitoral, massagers). They come with a motor inside that, you guessed it, vibrates. Just check out the wide variety of vibrators offered on this site. It's huge! It seems there are vibrators for everyone, and for everywhere.
Does that answer your question. My apologies if I just made it worse.