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