Whether you work in product management, IT, consulting, manufacturing or marketing you need a roadmap. This settings option allows users to completely customize the terminology that is used in Aha! to match what your team uses everyday.
Instead of Releases you might have multiple ongoing Projects, or perhaps your Features are called Stories. You might prefer Epics to Initiatives or Epics to Master features. The names you enter will be displayed everywhere except in the Settings screens.
You can customize the terminology by product under Settings -> Product -> Terminology. You need to have the permission level of Product Owner to customize the terminology.
It stands to follow that if you want to change your terminology, you may also have needs to customize other aspects of Aha! You can create custom feature types, statuses and workflows to ensure teams are following the right process. For Releases you may wish to create custom templates of phases and milestones to manage the success of your releases (or projects as it were).