What is wireless distribution system (WDS)?
The IEEE 802.11 standard defines a distribution system as the infrastructure used to connect access points. To establish a distributed WLAN, two or more access points are configured with the same service set identifier (SSID). Access points configured with the same SSID make up a single logical network within a single Layer 2 broadcast domain, which means that they must all be able to communicate. The distribution system is the method used to connect them so they can do that.
The most common use of a wireless distribution system is to bridge a WLAN spanning two buildings. The simplest WDS consists of two access points configured to forward messages to each other, working in conjunction with an antenna that enables line-of-sight communication.
In a wired distribution system, APs typically connect through an Ethernet switch.