What is the exact difference between mongod and mongos

Question

While I was looking into the MongoDB documentation, I found two different terms mongod and mongos.

While starting the server, I am using

Answer 1

Mongos = MongoDB Shard Utility, the controller and query router for sharded clusters. Sharding partitions the data-set into discrete parts.

Mongod = The primary daemon process for the MongoDB system. It handles data requests, manages data access, and performs background management operations.

This explanation of mongo replication and sharding really helped me understand it: https://dba.stackexchange.com/a/53705/106925