The mobile communication system where we are using all of our mobile phone is called Cellular Communication System.
What is Cellular Communication System ?
Cellular Communication System is a type of communication system that are operating with huge network of Cells.
Then, What is Cell ?
Cell is an area that can be covered by a fixed station (Basestation, NodeB, eNodeB, gNodeB).
Each Cell is configured by a set of specific physical properties that can separate it from neighbouring cells