Cascading is an important feature of 74HC595. Cascading helps to create multiple outputs. Similarly, you can cascade more modules.
Upload the following program to Arduino UNO. Change the value in customDelay() function to change the speed of running LED.
Shift Register Example
Turning on the outputs of a 74HC595 using an array
* 74HC595 shift register
* LEDs attached to each of the outputs of the shift register
//Pin connected to ST_CP (12) of 74HC595
int latchPin = 12;