The wireless operating modes
A wireless interface always operates in one of the following operating modes. The mode sets the main functionality of the wireless link.
AP – AccessPoint infrastructure mode
An Access Point acts as the Master device in a managed wireless network. It holds the network together by managing and maintaining lists of associated Stations. It also manages security policies. The network is named after the MAC-Address (BSSID) of the AP. The human readable name for the network, the SSID, is also set by the AP.
STA – Station infrastructure mode
The Station device connects to an access point by sending certain management packets to it. This process is called the Authentication and Association. After the AP sent the successfull Association-Reply, the STA is part of the network.
MON – Monitor mode
Monitor mode is a passive-only mode, where no packets are transmitted. All incoming packets are handed over to the host computer completely unfiltered. This mode is useful to "see what's going on", on the network.
IBSS – Ad-Hoc mode
The Ad-Hoc mode is used to create a wireless network without the need of having a Master Access Point in the network. Each Station in a Ad-Hoc network is managing the network itself. Ah-Hoc is useful for connecting two or more computers to eachother when no (useful) AP is around for this purpose.
WDS – Wireless Distribution System
The Distribution System is the wired uplink connection to an AP. The Wireless Distribution System is the wireless equivalent to it. So APs can communicate to each other over the wireless medium instead of the wired "backplane" system.