In music notation, an eighth rest is a pause in the music lasting for one-half of a beat, the same duration as an eighth note. It resembles a stylized number '7' drawn in the middle of the staff.
On the staff, an eighth rest looks something like this:
/\
---| /-----------------------------------------------------
|/
---/-------------------------------------------------------
/| *-/
-/-|/\----------------/------------------------------------
| | | /
|--|--|----------------------------------------------------
\ | |
--\|_/-----------------------------------------------------
|
\|