The SN74LS166AN is an 8-bit parallel-load serial-out Shift Register compatible with most other TTL logic families. This parallel-in or serial-in, serial-out shift register has a complexity of 77 equivalent gates on a monolithic chip.
The CD4014BC is an 8-stage parallel input/serial output shift register. A parallel/serial control input enables individual JAM inputs to each of 8 stages. Q outputs are available from the sixth, seventh and eighth stages.
The CD4015 is a Dual 4-bit Shift Register. It has a wide operating voltage upto 18V, hence can be used in high voltage applications. The IC is commonly used as I/O expander along with microcontroller to control multiple outputs like LED, LCD display etc..