Usually there is no need to access a Mysql db from a remote machine as the locahost access is usually enough. But there might be occasions when you want to have remote access, for example in the case you want to query your db from excel. For that you have to create a user for remote access:

#mysql -u root -p
password:
GRANT ALL PRIVILEGES ON *.* TO  'USERNAME'@'IP'  IDENTIFIED  BY  'PASSWORD';
FLUSH PRIVILEGES