The caching mechanism is used in computer systems to (A) allocate memory to different processes. (B) store frequently accessed data in a temporary storage area for quicker access. (C) ensure communication between memory and I/O devices. (D) manage network protocols and data transmission. (E) handel the system error.

The caching mechanism in computer systems is primarily used to store frequently accessed data in a temporary storage area for quicker access. Therefore, the correct answer is (B).

Here's a step-by-step explanation:

1. When a computer program needs to access data, it first checks the cache, which is a small amount of faster, more expensive memory.

2. If the data is found in the cache (this is known as a cache hit), the program can access the data quickly, avoiding the need to access slower, less expensive types of memory, such as RAM or a hard drive.

3. If the data is not found in the cache (a cache miss), the program will then access the slower types of memory to retrieve the data.

4. After a cache miss, the data is usually copied into the cache, ready for the next access.

5. The goal of the cache system is to increase the percentage of cache hits, which results in significant time savings for data access.