Why is it necessary to run both mongod and mongo.exe in windows? What's happening behind the scene?
What's the difference between these two?
As @Stennie explained it's exactly the other way around .. mongod is the daemon background process running the database server and mongo.exe is the interactive shell.
As such - both are running if you want to use the database from the command prompt / a console [CMD] window.
mongod
is the server daemon and mongo
(aka the mongo
shell) is the client console tool.