What is the function of a web adapter in an Esri Enterprise deployment?

The role of a web adapter in an Esri Enterprise deployment is crucial as it acts as an intermediary layer that facilitates secure communication between clients and ArcGIS Server. By providing a secure connection, the web adapter helps in authenticating and authorizing requests made by users, ensuring that only legitimate clients can access the services provided by the ArcGIS Server. This enhances the security of the entire system as it protects sensitive data and maintains control over who can access what services.

In essence, the web adapter serves to integrate web servers with ArcGIS Server, allowing for seamless interaction while enforcing security protocols. It also allows for the implementation of URL rewriting, making it easier to manage service URLs and improving user experience.

The other options focus on functions that do not accurately describe the primary purpose of a web adapter. Enhancing graphical performance is not within the purview of what a web adapter does; instead, it works on managing connections and security. Similarly, while a web adapter might assist in managing communication, it does not manage database connections or serve as a backup for services. Instead, it ensures that any communication between clients and the server is secure and properly authenticated.