hikerduane
sorry
I used climbing jargon because I posted in the climbing forum.
Piton = pointed, tapered pieces of chrome moly steel with eyes to clip carabiners into that are hammered into cracks too narrow to climb. Pitons can be hammered into cracks 1/8" One problem is that they damage the rock and after a while you have to use a wider piton. Piton scars are about 2 feet apart. People would hook a ladder to a piton, climb up it and hammer in another one 2 feet up and do it until they got to the top. This is called a "nail-up" or artificial climbing because you don't really climb, you instead go up a ladder.

Free climbing = climbing by holding onto rock features with your fingers and feet on the rock.

Bolt = actual bolts put into small holes drilled into the rock. The original bolts were about half an inch long and 1/4" in diameter and were originally used for hanging signs, not people. Modern bolts are 2" long and 1/2" in diameter.

Pro or Protection = anything you can attach to the rock for safety, now days we use spring loaded
cams
that slide into cracks and expand by mechanical means and have triggers to collapse them so the can be removed and do no damage to the rock.

Nuts = we originally actual threaded nuts with ropes through them, they were wedged into cracks for protection.

Friction climbing = climbing on steep totally smooth rock with no hand holds at all, merely by pressing your palms and balls of your feet against the rock and standing as erect as possible - legs straight up like walking down a sidewalk.

Aid slings - the same as standing on a ladder attached to a piton for artificial climbing. El Capitan was originally climbed with pitons and bolts, but now it "has gone free" mean climbed by "fair" means - no pitons.

Shoes = the modern climbing shoes are smooth and made of sticky rubber designed for the maximum friction on rock, but they only stick if the feet in them know how.

Belay knobs = a ope is 50 meters long, 165 feet. At the end of a rope length there has to a solid place to attach a rope and a belayer.

Belayer - the person who holds the rope tied to the leader. The leader places pro in cracks as he climbs and clips his rope through a carabiner on the PRO. If he falls, his rope is caught by the last pro. The rope in the belayers hands jerks as the load hits him. The rope is held by the belayer though, rather the belayer is tied to the anchor and the rope goes through a "brake tool" and he tightens his hands on the rope, but the brake actually "brakes" the fall.

Layback = hooking your fingers into a crack and laying backwards so that your arms are straight but your body is at an angle and your toes (in climbing shoes) are poked into the crack. You climb on the outside of the crack. Obviously if your lose a finger hold you are in a bad position and you fall, but the "belay rope" is there to catch you after you fall past your last "PRO". In the old days they climbed in front of a crack and reached into it to find a hold and twisted their feet to "lock" the into place to hold you so you could reach up for the next hold with your hands.
Jim
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These are my own opinions based on wisdom earned through many wrong decisions. Your mileage may vary.