Like to understand the linux "free" command with respect to cache and free memory
 

Was wondering if anyone can explain briefly the relationship of "cache" and free memory in the "free" memory command. Thanks.

From what I understand, the kernel cache's frequently used files in the RAM under cache. These files are only put in unused memory, and the kernel will give up any cached memory to any process that needs memory. In essence, your available memory is your free memory (unused at all), and the cached memory (being used to cache files). The second line of the 'free' command shows you what your actual free/used memory is.

Thanks very much and that confirms my understanding as well. Much appreciate taking the time to respond.