What "bolts" means in rock climbing

In rock climbing, bolts are metal anchors permanently drilled into the rock to protect climbers during their ascent. These bolts typically consist of a threaded steel rod, called a bolt hanger, which attaches to a steel hanger or chain, allowing the climber to clip their rope into the anchor. Bolts are used when natural protection such as cracks or crevices in the rock cannot be found or are insufficient. They are often placed by experienced climbers or trained professionals to ensure the safety of all climbers.