This device is a small transceiver you plug into a switch, router, or server. It can also turn optical signals back into electrical signals for copper cables. Among various optical module form factors, SFP (Small Form-Factor Pluggable). An SFP (Small Form-factor Pluggable) is a compact, hot-pluggable transceiver module that allows networking equipment — including switches, routers, servers, and media converters — to support different physical media, such as optical fiber or copper, without replacing the host hardware. SFP is an upgraded version of GBIC (Gigabit Interface Converter). What is An SFP Module? SFP means Small Form-factor. Understand the core function, compare data rates (1G to 25G), learn critical compatibility rules, and follow our 5-step checklist for selecting the perfect SFP optical module for your network build.