Support reactions are the forces that a structure needs to counterbalance the loads applied to it.
Propped Cantilever Beam: This kind of beam has three support reactions one vertical and one horizontal at the fixed end, and one vertical at the simply supported end.
Continuous Beam with Three Spans: A continuous beam that spans over more than two supports. Since it has three spans, it would have four supports.
Fixed Support Beam: A fixed support beam, also known as built-in beam, has both ends fixed into supports. Each fixed end would have three reactions (vertical force, horizontal force, and moment), for a total of six reactions.
Simply Supported Beam: This is a beam that rests on two supports at its ends. Each support has only one vertical reaction, amounting for total of two support reactions.