Does anybody know about Google Doubleclick?

[Click SSL]

I has found one interesting link before some time but I am not getting perfectly what it wanna say about.. Does anybody help me to know about Google Doubleclick?:confused:

[Abagail]

DoubleClick offers technology products and services that are sold primarily to advertising agencies and media companies to allow clients to traffic, target, deliver, and report on their interactive advertising campaigns.