Electric sockets

A lampholder is a wiring device used for holding a bulb and connecting it to power supply. There exist different kinds of lamp sockets, like Edison-screw lampholders, bayonet mounts and pins for halogen and fluorescent bulbs.
Edison screw lampholders used in homes come in 2 different sizes. The first one is E27 with the diameter of 27 mm. These are used for regular bulbs ...