Why is HDL known as the good cholesterol?

Does many things. Hdl removes cholesterol fromlaquesnin the artery wall but also has many other functions. It is an antioxidant, has anti-inflammatory features and protects the artery wall. It may even play a role in infection, .
It's being disposed. If you think of cholesterol as garbage, then the HDL is in the garbage trucks, being carried away from the cells, therefore the more , the better.