We learned how to add more pin spots so that we can add more inputs or outputs to the computer. Also we learned that these come in two way in a multiplexer and a shifter register.
In a multiplexer you can on send on piece of data to one of the outputs or take out the data one data point at a time. But, this action can be done within a second to the point the human eye can not catch it.
In a shifter register it make a lot of pins but data is sent to all pins at the same time. This data is “slowly” stored into shifter register. This allows us to turn on lots of light all at one time.