They are used to carry the weight of the vaulted roofs and walls.

The 'clustered' part of them is an ornate decoration that makes it look like a collection of pillars all squished together to make one big pillar flying buttresses they are exterior buttresses that have an arch shape and only connect to the wall at one point. celerstory 4th layer, and is basically just a series of big windows, and is where most of the natural lighting comes from clustered wall shafts the claims that arches sit on in the cathedral. Sometimes the triforium is just a set of arches with windows. triforium 3rd layer, is a smaller walkway/balcony above the gallery & arcade and separates them from the clerestory. the ribs are the skeleton of the vaults kind of and define the shape arcade 1st layer, separates the nave from the aisle gallery 2nd layer, is a walkway/balcony above the arcade (sometimes churches don't have them, and go straight to the triforium. ambulatory the equivalent to an 'aisle' but is specifically in the apse chapel smaller semicircular ejections around the apse/choir usually pointed arch arch with a pointed tip in the middle rib vault the ceiling on the interior of gothic architecture. is the space around the altar apse the large semicircle shape at the end of the church, containing the chancel. Narthex a large porch nave central part of the church, used for congregation aisle walkways/aisles on either side of the nave, separated by the columns of the arcade transept in a cross-shaped church, the transepts make up the arms of the cross (the short parts of the letter 'T') crossing the intersection of the cross in the cross shaped churches, (where the transepts meet the nave) chancel includes the choir/sanctuary.

Elevation novella