The process is called shearing, or clipping.
Shearing
shearing
Burrs in wool refer to the prickly seed pods from certain plants, such as burdock or thistles, that can cling to sheep's fleece. These burrs can be a nuisance during shearing, as they can damage the wool and make it more difficult to process. Additionally, they can irritate the sheep's skin, leading to discomfort. Removing burrs is important for maintaining the quality of the wool and the health of the sheep.
Chickens are plucked. Though this is true without first sheering a sheep. :)
Sheep grow wool. When the wool is shorn from a sheep it is called a fleece.
clean it
A fleece is what the wool is called when it is shorn from a sheep.
Once a year, in the spring, a shearer uses hand shears (similar to large scissors) or electric shears (similar to an electric razor) to cut the wool off the sheep. The sheep don't mind the process, and as soon as the weather warms up they're really glad to be rid of all that wool!
More properly, the raw material from which wool is spun is called fleece.
wool
Wool.
Wool