Riding in group can be daunting to begin with, a small mistake and down you go. Once you have learned the ins and outs though, it can be a huge benefit to you and your fellow riders during a long race\ride.
In a road bicycle race, the peloton (from French, originally meaning 'platoon') is the main group or pack of riders. Riders in a group save energy by riding close (drafting or slipstreaming) near (particularly behind) other riders. The reduction in drag is dramatic; in the middle of a well-developed group it can be as much as 40%.[1][2] Exploitation of this potential energy saving leads to very complex cooperative and competitive interactions between riders and teams in race tactics.
The peloton travels as an integrated unit (similar in some respects to birds flying in formation) with each rider making slight adjustments in response to their adjacent riders (particularly the one in front of each). When developed, riders at the front are exposed to higher loads, and will tend to slip off the front in order to rejoin the pack farther back. With sufficient room to maneuver, this may develop into a fluid situation where the center of the peloton appears to be pushing through its own leading edge.