Whats the difference of Podfile post_install config loops in build_configurations

Question

I've seen many different answers some with this loop config:

post_install do |installer|
 
  installer.pods_project.build_configurations.each do |config|
     config.build_settings['CODE_SIGNING_REQUIRED'] = "NO"
     ...

others with:

installer.pods_project.targets.each do |target|
    target.build_configurations.each do |config|
      config.build_settings['CODE_SIGNING_REQUIRED'] = "NO"
      ...

They seem to have the same result apparently... but one goes through each target in targets then cycles through each config in build_configurations of that target... whereas the other just goes through each config in build_configurations at same level as targets (level of pods_project)

are these the same thing? can some one please clarify whats is happening here?

if possible, also provide a link to where can I learn more about these Podfile post_install configuration options and all its possibilities