In music notation, a whole rest is a pause in the music lasting for four beats, the same duration as a whole note. It is drawn as a short thick line just below the second staff line from the top.
On the staff, a whole rest looks something like this:
/\
---| /-----------------------------------------------------
|/
---/-------------------------------------------------------
/|
-/-|/\-----------------------------------------------------
| | |
|--|--|----------------------------------------------------
\ | |
--\|_/-----------------------------------------------------
|
\|