The small form-factor pluggable (SFP) is a compact, hot-pluggable network interface module used for both telecommunication and data communications applications. ... SFP transceivers exist supporting synchronous optical networking (SONET), Gigabit Ethernet, Fibre Channel, PON, and other communications standards.
Why do we need SFP module?
What Are the Functions of SFP modules? SPF modules facilitate high-speed communication between switches and network components such as routers and other devices. It is mainly used with copper or fiber optic cables. Its small form factor makes it ideal for areas that may not be very accessible.