There are two main types of connections used in steel frame formwork systems: bolted connections and welded connections. Bolted connections involve the use of nuts and bolts to secure the different components together, providing flexibility in assembly and disassembly. Welded connections, on the other hand, involve fusing the structural elements using heat, resulting in a permanent and strong connection. Both types of connections have their advantages and disadvantages depending on the specific requirements of the construction project.