A PON is a type of telecoms network that uses fiber optic cables to transfer data. It is "passive" because it sends data from a central place to numerous locations using unpowered splitters.

Providers and NSPs use PONs as a low-cost method of giving clients access to the Internet. A point-to-multipoint (P2MP) system like a PON offers a more effective method of data transmission than a point-to-point network. In comparison to constructing straight lines to each location, the primary transmission line can be divided into 32 distinct lines.

While the various targets are known as optical network units, the center site of a PON is also known as the optical line terminus (OLT) (ONUs). The terms fiber-to-the-neighborhood (FTTH) and fiber-to-the-curb refer to lines that end outside of structures (FTTC). The terms fiber-to-the-building (FTTB) and fiber-to-the-home (FTTH) refer to lines that reach structures in their entirety (FTTH).

All PONs use unpowered splitters and optical lines, but there are various variations. A summary of the various PON varieties can be found below.

• APON is an early version that dates back to the middle of the 1990s and transfers data using asynchronous transfer mode (ATM).
• The first "broadband" PON, BPON, can transmit data at a rate of 622 Mbps, which is equivalent to the bandwidth of an OC-12 (STM-4) connection.
• GPON, also known as the ITU G.984 standard, is a "gigabit-capable PON" that allows 2.488 Gbps downstream and 1.244 Gbps upstream.
• The most widely used PON version, known as EPON or GEPON, sends data as Ethernet packets at up to 10 Gbps both downstream and upstream.