What is "WiFi Direct"?
Wikipedia explains it as follows:
Wi-Fi Direct, previously known as Wi-Fi P2P, is a standard that allows Wi-Fi devices to connect to each other without the need for a wireless access point. This allows Wi-Fi Direct devices to directly transfer data between each other with greatly reduced setup. Wi-Fi Direct works by embedding a limited wireless access point into the devices, and using Wi-Fi Protected Setup system to negotiate a link. Setup generally consists of bringing two Wi-Fi Direct devices together and then triggering a "pairing" between them, using a button on one of the devices, or systems such as NFC.
Android supports WiFi Direct as of version 4 (ICS). An exception is Samsungs Galaxy S2, which already had this support added by its manufacturer in Android 2.3 (Gingerbread).
- ad-hoc-networks: WiFi Direct is a kind of ad-hoc network, as it does not require an intermediary such as e.g. an access point
- nfc: NFC can be used for pairing WiFi Direct devices
- wi-fi: the more generic tag