What is SFP port?
SFP means small form-factor pluggable it is used in network and storage devices and is a hot swappable interface that connects fibre or RJ45 cables between switches and the network.
In the picture above you can see two SFP ports one sfp in switch.
SFP+ Modules
In 2006, SFP+ specification brought speeds up to 10 Gbit/s and the SFP28 iteration is designed for speeds of 25 Gbit/s. The SFP replaced the larger GBIC in most applications, and has been referred to as a Mini-GBIC by some vendors.
Wikipedia