PCB connector usually means one of two types of connectors: board-to-board connector and wire-to-board connector. Board-to-board connectors usually make the unit easier to maintain when connecting boards and replacing units.
For this purpose, a connector is attached to the PCB using the THT or SMT process. Connecting elements such as flat cable connectors (FFC), jumpers with LIF/ZIF plugs or crimp contacts or special magnetic connectors then engage in this connector.
PCB connectors connect PCBs to PCBs or even displays and LEDs and transmit power and/or signals - a "mix-and-match" concept that allows you to integrate versatility and cost savings into your design. In the field of power supplies, PCB connectors are used to supply electrical power to the assemblies of a rack.
As an alternative to the classic PCB connectors, you can also consider using a flexible PCB, which scores in terms of reliability / variability.