What do two-in-one and three-in-one laminates mean?

The two-in-one connector of panel furniture is very different from the three-in-one connector.

Two-in-one connectors are mostly used to connect partitions because it is simple and quick to use. It can also be used when standing and assembling cabinets. Two-in-one is convenient to use, but it is not strong. Three-in-one connector is mainly used to connect the side plates, upper and lower plates and fixed partitions of the cabinet. Compared with the two-in-one connector, the three-in-one connector is much stronger.