What term describes an in-memory cache of a database?

The correct term that describes an in-memory cache of a database is known as a data cache. This specific term refers to the practice of storing frequently accessed data in a location that's quicker to access than a traditional database, which can significantly enhance performance by reducing the time needed to retrieve information.

A data cache keeps a subset of data from the database in memory, allowing for much faster read operations since accessing RAM is significantly faster than accessing disk storage. This technique is commonly used in various applications to accelerate data retrieval processes and improve overall application responsiveness.

In contrast, a database server refers to a system that provides database services, while a memory buffer is a storage area that temporarily holds data being transferred between two locations, and a dataset generally refers to a collection of data, often used in the context of data processing or analysis rather than specifically indicating an in-memory cache.

Thus, understanding in-memory caching as a performance optimization strategy is essential in software development, especially when working with large datasets or applications requiring high-speed data access.