mysql memory questions

I am trying to work out what memory the following uses on the server, either ram or hard disk space
i want to find out what memory for the following key_buffer_size and sort_buffer_size and myisam_sort_buffer_size

If I understand your question correctly, everything you’ve listed refers to in-memory (RAM) buffers. The only time disk will be used for these is if you don’t have enough RAM, and your operating system begins swapping the contents of RAM out to disk.