In the readline info pages : info bash -n Commands For KillM-y      Rotate the kill-ring, and yank the new top.  You can only do this      if the prior command is C-y or M-y. understand that C-y pastes the last killed text, but I couldn't figure out what M-y exactly does.Can you explaine
What does rotate the kill ring mean?
bash;readline
M-y undoes the last yank, rotates the lists of all kept kill strings, and yank the new top of the list.  Try this example: type the 5 characters a b c (no newline)position the cursor (with C-b) in front of the c and type C-k to kill the c onto the top of the kill ring. Position the cursor 2 chars to the left and type C-k to kill the b, and again to the start of the line and type C-k to kill the a.Now type C-y and you yank the a from the top of the list.Type C-y again, you just get another a, but if you immediately type M-y the a is removed and replaced by b. If you now type another C-y you get b, not a, because the kill-ring has been rotated. Similarly, a M-y will replace the b by a c.When you type the sequence C-y followed by lots of M-y you get each of the kill-ring strings, one by one.