The drummer's role in any band is to play time that the rest of the musicians can rely upon. The drums provide a compliment to the other instruments. Beyond that, the drummer adds to the dynamics and feel of the song.
To illustrate this, I put together a couple videos that focus on a type of drum beat.

The first video is a rock beat with a hint of swing a la John Bonham of Led Zeppelin.

The second video is an up-tempo train beat often used in country music. But, check out Golden Earrings' "Radar Love" (1973) to hear it used in rock.

The third video is a left-hand shuffle (mostly!) The shuffle beat was originally a blues groove but can be found in rock, pop, and funk. Billy Joel's "Only the Good Die Young" incorporates a shuffle beat. 

Hope you enjoyed these videos!
Have some fun, use them as a drum track and add your own music.
Feel like sharing? Post a link of your music created and inspired with one of these drum tracks on my   Facebook page.