What are SFP ports on a Gigabit switch and what are they used for?

What are SFP ports on a Gigabit switch and what are they used for? slot sfp Home Media Converters SingleMode Netfox 10100 Mbps 1GE SFP Slot – Ext PS Netfox 10100 Mbps 1GE SFP Slot – Ext PS SKU: NF-MC-GE-SFP-EXT Categories: slot planet 1Gbps TP 8-Ports + 110G SFP 4-Slots SFC8100-BP_2x2 10G L2 Industrial 1Gbps TP 8-Ports + 110G SFP 4-Slots + BYPASS 2x2 SFC8100-BP_4x4

slot planet Industrial Gigabit Unmanaged PoE Switch with SFP slot DIS-100G-5PSW Product Status: Live Live 4 x 1001000BaseT PoE ports, 1 x 1001000BaseSFP slots; 120 W

slot features SFP modules may can be used in SFP+ slot, but a SFP can never be connected to a SFP+ module For their different speeds, transmission distance Industrial Gigabit Unmanaged PoE Switch with SFP slot DIS-100G-5PSW Product Status: Live Live 4 x 1001000BaseT PoE ports, 1 x 1001000BaseSFP slots; 120 W