Right-angled bends are a type of corner joint used in carpentry and other construction projects. They are formed by two pieces of material that meet at a 90-degree angle, creating a corner. The term 'ELLS' is an abbreviation for the word 'ELLIPSES, ' which is a shape that has two curved lines that meet at a right angle. ELLS are often used to create right-angled bends in carpentry and other construction projects.