Vanitygen isn't a bruteforce tool, it can't search full addresses, it's only for generating "vanity" addresses.
Basically it is a bruteforce tool that could potentially bruteforce whole adresses. But since adresses are to complex it is not possible to find a complete adress in any reasonable time. So people stick with just a tiny part of the adress that they bruteforce.
Yes, it's the underlying method of the tool as stated in the OP.
But it already has a limit of 27characters prefix (
including '1'), more or it will return with an error.
So I wouldn't call it a bruteforce tool unlike BitCrack; I'd stick with:
Vanitygen is a command-line vanity bitcoin address generator.