In the previous chapters you've always needed a user ID and password to manage the GeoServer configuration. However, you could acquire the layers and maps with anonymous access. For GeoServer security, you used the default settings that are configured to provide free access to your data for everyone.
While this is quite understandable when you are developing your application, it is not often a good idea for a real site.
There could be many different reasons for you wanting to hide your services or at least a part of them. Your maps could be integrated into a site with a security system requiring your user to log on.
Why should maps be freely available? Users may be linked to different roles, with some confidential data only visible from a few of them. GeoServer security can help you secure your data, both in simple and complex cases. If you just want to publish your maps or if you are going to work with the data of a large corporation, you should...