What is a full-thickness, near full width tear in the supraspinatus tendon in the shoulder? does this require surgery to repair? need explaining?

That is a tear that is essentially the full way through the supraspinatus tendon of the shoulder. Though most tears cannot heal on their own, you can often achieve good function without surgery. If, however, you are active or use your arm for overhead work or sports, surgery is most often recommended because many tears will not heal without surgery. Best to see an orthopedic surgeon to discuss.