The most popular and widely used shift register is the 74HC595, often simply referred to as the “595”. What makes the 74HC595 so useful is that it can control eight different output pins while only requiring three input pins from your Arduino.
74HC595 IC is a 16-pin shift register IC consisting of a D-type latch along with a shift register inside the chip. It receives serial input data and then sends out this data through parallel pins.