In music notation, a staccato is an articulation mark drawn as a dot just above the note-head, or just below it if the stem points upward. It indicates that the note should be played short and disconnected from the note following it, about half the duration of the beat. It does not mean that the note should be played louder or more sharply, only more briefly. The word means "detached" in Italian.
It looks something like this on the staff (complete with time signature and a quarter note scale):
/\
---| /------------------------------|--------------------||
|/ | | ||
---/--------------------------------|---|----|--------.--||
/| 4 | | | | . * ||
-/-|/\----------------------|----|--|---|----|---*---|---||
| | | 4 | | | | | * | | ||
|--|--|----------|-----|----|----|--|--*----.---|----|---||
\ | | | | | * | . | | ||
--\|_/-----------|-----|---*----.---|-----------|--------||
| | * .
\| -*-- .
.