Data and Servers

So sorry with all these question lately, but so is data(database) relation is handled through networking. So I made a post recently about creating a MMO. So I am guessing the player info needs to be stored at some database. Does the connection with database handled at network level? I guess to simply asking is there some special thing I need to know about database, how do I implement it, what are the best practices.

Also I want to create a mmo similar to Runescape where you can login and...

Data and Servers