YII2 Config File Confusion?

What is the main config file here for Yii2?

main-local.php

main.php

params-local.php

params.php

Do I have to keep all these?

In the contents I see:

$config

$params

They both look about the same in format, I don’t know when adding something where to put it in.

Please be kind, I am just learning.

Are you on the advanced app template? In any case, see here. This can be confusing at first, but it gets better in time and you will soon see the merits of this. I promise ;) Rule of thumb: Everything ending in [font=“Courier New”]-local.php[/font] should not end up in version control as it is supposed to override the defaults set in the other files with values that are correct on your system only.