What are beams and what was their use?

The beams are two wooden cylinders, as wide as the loom, located in front and behind the loom. After warping, the threads that made up the warp were wound onto the rear beam, while the fabric was wound onto the front beam as it was produced. For this reason, they were called the warp beam and the fabric beam respectively.
Both the rear and front beams had a manual device, called a tensioner: on the warp beam, the tensioner allowed the threads to be tightened or loosened, while on the fabric beam, it allowed the fabric to be wound so that weaving could proceed when the space between the comb and the fabric ran out.