what are those technical details from mysql database to be provided to Power BI

Dear Experts
We are having web application which is developed using apache,  php and mysql for database.  To develop reporting and analysis we have decided to use Power BI tool and hire Power BI developer and install Power BI desktop  to collect/process/deliver reports and analysis on local network, power BI desktop connects directly to the applications Mysql databasever.
Please help me understand what details the power BI developer requires other than reporting requirements and reporting logic. please help me the following
what are the technical details from mysql database side to be provided to the Power Bi developer ( in our case power BI  desktop directly connects to MySql database) little I know is to provide the  database name, table names and some talk about columns names I am not clear on this can you please help me to understand (what exactly column name mappings is ) i want to ask the complete requirement to the mysql database administrator please help on this.