Ad-hoc networking means that each computer talks to each other directly without the “supervision” of a device such as a router. This arrangement is sometimes called peer-to-peer networking.
If there are enough computers involved, an ad-hoc, or peer-to-peer network, can begin to form a kind of grid, or mesh. This gives peer-to-peer networks in some applications a great deal of power, although there's no really good way to administer a peer-to-peer network, and security remains an issue.
The Wi-Fi standards specify two different configuration modes, ...