In music notation, a sixteenth note represents one-fourth of a beat and is represented by a filled circle with a stem and two flags or beams. It is so named because it lasts for the duration of one sixteenth of a whole note. Also called a semiquaver.
A series of sixteenth notes on the staff looks something like this:
/\
---| /-----------------------------------------------------
|/ |\
---/-----------------|\-------*----|\|\--------------------
/| * |\ *| | |\|\
-/-|/\---------|-----|/----|-|-----|-|-|\|-----------------
| | | /| | | | * | | |
|--|--|-------\|----*------|/|------*--|-|-----------------
\ | | \| |/ * |
--\|_/----------------------------------*------------------
|
\|