A makeup product used along the lash-line that is designed to add definition to and emphasize the eyes.
Eyeliner brings out your eyes, and can be applied with various techniques to make them look larger, more elongated, etc.
If you have trouble with eyeliner, try using a pencil as smoothly as you can, and then smudge the line just a bit with a Q-tip after you apply it...that way you don't have to worry about being as precise, and you get a nice smoky effect.
Need a suggestion? Try one of these!
Creamy formula goes on smoother than most pencils
Easy to use felt tp liquid liner that stays put
Great cream eyeliner that lasts all day and doesn't cost a fortune