Bots, or being more precise, the 'status' of being a bot includes a users edits being hidden in the recent changes by default.
The main purpose of this feature is, hiding automated processes fulfilled by specific bots in these changes. Such processes may include the correction of often made mistakes, optimizing or fixing layout problems and other stuff, leaving specific notices behind or not - depending on their program routine.
On the OGN wiki, there is no 'real' bot at work, so everything is done manually.
If you need more information on this topic, take a look at the respective page at en.wikipedia.org.