The terms ‘dildo’ and ‘dong’ are sometimes used interchangeably but they are actually different types of sex toys.
The main difference is that a dildo has a distinct base, but a dong does not. The base can resemble testicles or be flared so the dildo can be mounted to a surface or attached to other sex toys, such as a harness or sex machine.
Strictly speaking, neither dildos nor dongs vibrate. Those that do can also be considered vibrators.