Gmod Donation System Mysql Question

Okay so in the gmod donation system it has 2 files in which I need to input MYSQL info:
One of them goes onto the website, the other goes into the game server files.

Here is the template for each:

Game server file:

local DB_HOST = “” <----- What do I put here?
local DB_USERNAME = “I put MYSQL Username here”
local DB_PASSWORD = “I put the password here”
local DB_DATABASE = “I put the database name here”
local SERVER_ID = “I put my server id here”

                                                                                                 Website file:

                                                                                                define("DB_HOST", "I messaged my webhost he told me to put "localhost" here);  
                                                                                                define("DB_USERNAME", "I put MYSQL Username here");
                                                                                                define("DB_PASSWORD", "I put the password here");
                                                                                                define("DB_DATABASE", "I put the database name here");          

The only thing confusing me is what do I put in the DB_HOST or the file that goes into the actual game server like is there a db host for my game server or something?
Please help me.

Yes if your sql is hosted on the same machine as your gmod server you would use localhost. Otherwise it would be the address of whatever machine is hosting your sql database.

your mysql server ip