What is the purpose of cache in a computer system?

The primary purpose of cache in a computer system is to store data for faster access. Cache memory is a small but very fast type of volatile computer memory that provides high-speed data access to the processor by holding frequently accessed data or instructions. By keeping this information closer to the CPU, the system can significantly reduce the time needed to read data from the slower main memory (RAM), leading to improved performance and efficiency in processing tasks.

In contrast, the other options address functions that do not fully capture the role of cache. While increasing storage capacity typically refers to the hard drive or SSD, running applications is primarily dependent on the operating system and main memory, and managing user interfaces relates more to software design and user interaction rather than the role of cache in data storage and retrieval. Therefore, the focus of cache memory remains on optimizing speed and access for frequently used data, solidifying its purpose in enhancing overall system performance.