Gigabit optics for access switches and campus uplinks. 1000BASE-SX for multimode runs, 1000BASE-LX for single-mode links up to 10 km, and 1000BASE-T when you are running copper.
At gigabit the choice comes down to the cable already in the ground. Orange or aqua
multimode fibre takes an SX module at 850 nm. Yellow single-mode fibre takes an LX at
1310 nm and will carry 10 km. Cat5e or Cat6 copper takes a 1000BASE-T module, good
for 100 m.
Vendor coding still matters at 1G: a Cisco switch expects Cisco coding even on a
cheap access link. We match the part number to the platform you name, and refurbished
stock is link-tested in matching hardware before it ships.