How does Email work

I would like to know how Email works . I am still new in the field of web dev’t and have created my own website . After registering my domain ,and hosting my site , i would like to be able to raeceive mail @mydomain_name.com. In addition i would like other users to be able to create accounts and access their email @mydomain_name.com. What does it take to be able to do this ? ….Thanks (Ayub)