What Is A Drum Head?
A drum head is the film (usually made from mylar) that is stretched over the drum which you hit/play.

What Is A Batter Head?
A batter head is the drumhead on the side of the drum you hit/play.

What Is A Resonant Head?
A resonant head is the drumhead on the under side of the drum which is not hit/played.

What Are The Different Types Of Drum Heads Available?
There are many types of drum heads available that all fit into 2 basic categories: 1 ply and 2 ply. 1 ply means the head is made from just 1 layer of plastic and 2 ply is made from 2. Single ply heads are usually used as resonant heads because they are thinner and more resonant. Double ply heads are normally used as batter heads because they are thicker and more durable.

How Do I Measure My Drums To Know What Size Heads I Need?
Measure from inside the hoop on one side of the drum to the inside of the hoop on the other side of the drum.

How Often Do I Need To Change My Heads?
This is usually down to the player. Some players like to use old drum heads because they produce a sound they like. Some players even change their heads after each gig. The normal amount of time people keep drum heads on is a copule of months. NEVER swap the batter and the resonant heads over! Having damaged resonant heads will make your drums sound terrible!