What is the purpose of using custom Visualforce error pages?

Using custom Visualforce error pages serves several important purposes, one of which is to provide a branded experience for authenticated users. When users encounter an error while navigating a community, a standard error page may not align with the brand's look and feel, potentially leading to confusion or a negative user experience. By implementing custom error pages, organizations can ensure that users, especially those who are authenticated and have access to specific community resources, see a consistent design that reflects the overall branding strategy. This not only reinforces brand identity but also enhances user trust and overall engagement, as users are more likely to feel at ease in a familiar environment, even when things go wrong.

The other options do not adequately encapsulate the primary purpose of custom Visualforce error pages. While preventing unauthorized access or restricting error notifications may be relevant for broader site management and security, they do not focus on the user experience aspect that custom error pages are intended to address. Hiding errors from all users may seem beneficial for security, but it risks creating confusion or frustration if users are left without guidance when issues arise.