Molars are the back three teeth on each side of each jaw. These are the main teeth that grind food.
The first permanent molars, called "6-year molars," come in between the ages of 5 and 7. The second permanent molars, "12-year molars," come in when a child is between 11 and 14 years old. Normally, an adult has 12 molars.
WebMD Medical Reference from Healthwise