Configuration Management in Drupal 7 isn't as simple as its equivalent in Drupal 8. In Drupal 7, almost the entire configuration set on a site is stored in the database by default. This includes simple variables, content types and field configuration, settings from custom or contributed modules, and so on.
Using the database to store settings makes it really hard to track configuration changes or roll back a bunch of settings to a state defined earlier.
Unfortunately, there is no real standard for Configuration Management in Drupal 7, but there are several ways to manage site and module settings in the code.
We will take a short look at the following five different approaches: