When someone is learning how to play the drums they must first develop the relationship between their right and left hands. This is done by practicing the 40 main drum exercises or rudiments (these are the equivalent of scales on a piano). The main ones are single strokes which are right-left-right-left... and double strokes which are right-right-left-left-right-right... Some of the harder ones include the para-diddle which is played by hitting right-left-right-right-left-right-left-left...
Other things to learn include simple beats that are made up by the hi-hat, the snare drum and the bass drum. Beats are the most important part of drumming. Beats are played in bars, these are the lengths of time where the beat is repeated. During a song the beat is repeated until it comes to a changing section, depending on the song the drummer can play a little solo at the end of the bar. This is called a fill.