IC sockets are generally for preventing damage to IC’s from soldering and while testing multiple circuits. These are made from Black Thermoplastic and tin-plated alloy contacts. One end is notched to aid in identification.
They can be mounted end to end to suit longer IC’s.. Required for sensitive ICs which are temperature sensitive and cannot be soldered to the board or at places where the IC needs to be replaced and for micro-controller based applications where the IC needs to be removed for programming.