Carabiners are among the most used tools in climbing. There are several different kinds, such as autolocking, screw gate, and regular carabiners. Regular carabiners are used in tools like quickdraws, nuts, and cams.
Quickdraws are what most climbers use to go up routes. Usually an established climbing route will have bolts already installed in the rock, and climbers clip in quickdraws as temporary protection. A quickdraw is made up of two carabiners attached on either end of a "dog bone", or nylon strap.
Anchors are what climbers tie into at the top of a route, usually using two quickdraws and rethreading the rope. Anchors usually attach to chains, "mussy hooks", or loops that are attached to permanent bolts.
"Trad", or traditional, climbers use cams to wedge a loop into an existing crack in a rockface that does not have established bolts. A climber pulls a lever and it compresses the cam, then upon release expands in the crack. The climber then clips their rope into the other end of the cam.
Also used in trad climbing, nuts are jammed into smaller cracks in the rock face, and function essentially the same as a cam, but without the moving parts. Nuts can also be called chocks, stoppers, or tapers.
A current solution to removing trad gear from routes is to use a nut tool to wrench out the gear.
Lead climbing consists of one climber "leading" the route. The climber climbs with the rope underneath them, and periodically clips the rope into quickdraws for protection. When a climber falls above their quickdraw, they actually fall twice the height at which they were above the quickdraw. This leads to a "whipper", or a fall that is caught abruptly.
When a lead climber reaches the top they make an anchor and rethread the rope through it, making a "top rope" climb. In a top rope climb the rope hangs down from the top, and the climber doesn't need to clip into quickdraws. The distance a climber falls depends on how much slack their belayer leaves in the rope.
A GriGri (or "birdie") is a belay device that auto-locks. It is one of the most common belay devices used. As the belayer pulls rope through it it automatically catches the rope should the climber fall. To give slack, lower, or release the rope, the belayer just has to pull back the lever on the top. Some GriGris have a "panic" function, where if the lever is pulled back too hard and too fast it will automatically lock up.
An ATC or "tube" is the other most common belay device. A climber puts a bight of rope through a slot and clips a locking carabiner onto that bight. The slack rope goes out the front of the slot, away from the belayer, and the weighted side of the rope is closest to the belayer and goes up to the climber. In order to catch a climber that is falling the belayer must pull the slack rope down at a 180 degree angle from the slot, creating a friction lock.
For indoor climbing "route setters" put up holds to make routes. Those holds are usually secured with a t-bolt, which is a male bolt that screws into a female socket that is nailed into the wall in a manner that it does not twist.
Most climbers use two rating systems to determine how hard a climb is. YDS or "class 5" ratings are used for trad and sport climbing (an umbrella term for lead and top rope climbing), and usually are on a scale of 5.1 to 5.14d, with letters designating another step of difficulty within that level. The v rating system is used for bouldering and ranges from VB (V basic) to V14. Every so often the scales are increased when a new "higher" level of difficulty is established.
Hard gear is the umbrella term for any gear that is solid and made of aluminum or similar materials. This includes nuts, cams and carabiners. Composite gear, such as a quickdraw (two carabiners on either end of a "dog bone", or nylon strap) is also sometimes called hard gear.
Soft gear is an umbrella term for items such as rope, slings (long nylon straps used to carry hard gear in a "rack" or as personal anchors), and cordelette.
A sling is usually a loop of nylon that is typically 2-4 feet long. Slings can be used to carry gear or as a personal anchor system (PAS), and is almost always made of nylon.
The "crux" of a climb is where the hardest move or set of moves are. This is essentially the hardest part of the entire route or problem, and may not always be at the end of the climb.
A whipper is a hard fall, which feels like the climber is being "whipped" up by the rope. The force of a fall is usually calculated using twice the distance one falls from their nearest anchor or bolt.
Climbers "clean" a climb by removing their gear as they are lowered. When a climber sets up the top anchor, they remove all the quickdraws or gear they placed on their way down.