The 74HC595 is an 8-bit Serial In – Parallel Out Shift Register, i.e. it can receive (input) data serially and control 8 output pins in parallel. This comes in very handy where do not have enough GPIO pins on our MCU/MPU to control the required number of outputs.
It is often used in projects where relatively a large number of LED’s has to be controlled through the Microcontroller.
It can be used to interface LCD screen since they can acts as the data bit for the LCD displays.
It can be used to control 5V loads like relays through a 3.3V microcontroller since the high-level voltage is only 3.15. So if you are looking for an IC to save on your GPIO pins on the Microcontroller then this IC might be the right choice for you.
