Explain memory usage categories.

Memory usage in a system can be categorized into several key areas:

1. Total Memory:

   • The total amount of physical RAM installed in the system.

2. Free Memory:

   • Memory that is not being used by any processes and is available for allocation.

3. Used Memory:

   • Memory that is currently allocated to processes. This includes both actively used memory and memory that is cached or buffered.

4. Buffer/Cache Memory:

   • Memory used by the kernel to cache data for faster access. This includes:
     • Buffers: Temporary storage for data being transferred between two locations (e.g., disk I/O).
     • Cache: Memory used to store frequently accessed data to speed up retrieval.

5. Swap Memory:

   • Disk space used as virtual memory when physical RAM is full. It allows the system to continue operating by moving inactive pages from RAM to disk.

6. Available Memory:

   • The amount of memory that can be allocated to new processes, which includes free memory plus cached and buffered memory that can be freed if needed.

Understanding these categories helps in monitoring system performance and diagnosing memory-related issues. If you have more specific questions or need further details, feel free to ask!