Multi-pitch climbing is the ascent of climbing routes with one or more stops at a belay station. Each section of actual climbing between stops at the belay stations is called a pitch

Pitch (vertical space)

-Climbing:In rock climbing and ice climbing, a pitch is a steep section of a route that requires a rope between two belays, as part of a climbing system...

. The leader ascends the pitch, placing gear and stopping to anchor themselves to the belay station.

The reason for the stops can be determined by choice, convention or necessity. For example:

• The rope is too short to do the entire route in one pitch (necessity).
• The leader has run out of protective gear (necessity).
• There is a convenient protectable
  Protection (climbing)
  To make climbing as safe as possible, most climbers use protection, a term used to describe the equipment used to prevent injury to themselves and others.-Types of climbing:...
  
   ledge, or fixed bolts
  Bolt (climbing)
  In rock climbing, a bolt is a permanent anchor fixed into a hole drilled in the rock as a form of protection. Most bolts are either self-anchoring expansion bolts or fixed in place with liquid resin....
  
   placed by previous climbers, at the location for a belay station (convention).
• The leader chooses to rest or exchange leads before the next section of the climb (choice).

The general purpose of these stops is to allow the second

Second (disambiguation)

Second is a unit of time.Second or Seconds may also refer to:* 2 , as an ordinal * Arcsecond, a unit of angle* Second of right ascension, in astronomy...

 to ascend to the point of the lead climber while collecting the protective gear from the route in the course of the lead climber's ascent. At the belay station, the protective gear is collected, possibly exchanged to a new leader, and the leader of the next pitch ascends the route.