Defence turrets are very powerful automated projectile or laser firing weapons. They're often protected or armored. It can aim and rotate over many degrees.
Station Defence Turret Edit
Station Defence Turrets are incredibly lethal and shoot any ship that violates station regulations. There's white text on the turret that says "Loitering is a crime."
Ground Based Defence Turrets Edit
There are small ground based anti-ship/anti-air version defence turrets to protect settlements and surface ports.
Anti-Ground Defence Turrets are small turrets for ground defense against srv's.
Anti-Air Defence Turrets can also be anti-ship and anti-air pictured below.
Big Defence Turrets have barrels as wide as an SRV. They're located near settlements and surface ports.
A Defence Platform is a large turret. The sensor range before a trespassing warning at low security is 728m. The sensor range before a trespassing warning at medium security is 1.6km for ships. However this distance depends on where the defense platforms are placed.