Question

What is device which changes serial data to parallel data?

Answer 1

So most familiar of parallel to serial data converter is multiplexer..The reason being in multiplexer we provide  2n input bits and corresponding to that we get 1 bit as output according to the selection lines.

On the other hand , serial to parallel data converter is demultiplexer(decoder as well)..where we have one input (in case of demultiplexer) or one enable input(in case of decoder) but we have 2n bits as output bits