AGM, or Absorbed Glass Mat, batteries are designed for ATV use. They are a specialty battery so they usually cost a bit more. However, they do not sulfate or degrade as easily as other types of batteries. There is a lower chance of hydrogen gas explosion or corrosion when using these batteries. The AGM batteries are the safest lead acid batteries you can buy.
Since an ATV is normally only used a few times a year and left sitting all winter, the batteries that supply the power usually only last 2 seasons. With an ATV battery, you must keep these batteries from sulfating or buy a new one. You can buy products to prevent and reverse sulfation. Or you can use a chemical battery additive to improve battery life and performance.