Wireless links differ from switched point-to-point Ethernet because several stations can contend for the same radio channel and cannot assume that every transmitter hears every other transmitter.

Wi-Fi organizes local wireless communication around radio channels, access points and stations. Frames still have link-layer addresses, but the medium is shared and transmission quality varies with interference, distance and competing users.

A wireless sender cannot reliably detect a collision while transmitting in the same way classic wired Ethernet could. Wi-Fi therefore uses collision-avoidance techniques: stations sense the channel, wait when it is busy and introduce randomized backoff before transmission.

Successful frames are commonly acknowledged at the link layer so losses can be retried locally.

Wireless networking is thus not merely “Ethernet without a cable”: the physics of a shared radio medium changes access control, reliability and performance.