Programmable chips such as EPROMs or microcontrollers attached in IC sockets during prototyping, allowing the devices to be quickly removed from the circuit for programming, then reinserted for testing.
Some integrated circuits are extremely sensitive and may damage by the heat from soldering, so attached in IC sockets for protection and easy replacement if failures occur.
Most production devices use chips soldered directly to the printed circuit board, as the chips never need to be removed. Some applications, however, use IC sockets, which allow chips to be inserted and removed without the use of a soldering iron.
They are available in different types and sizes.
Here this IC base is of 40 Pins, means any ICs having 40 pins, can be inserted in 40 pins IC socket or base.