A PCB can contain many different connectors. Some of these shall exist on the edge e.g USB connector, power barrel connector, Ethernet connector, Serial port, HDMI, DVI, Parallel port e.t.c. All these things are components that are soldered onto the PCB near its edge.
Then we have a separate scenario where the PCB itself has copper contacts of regular size and pitch that are designed to be sided into another connector on a motherboard or backplane.
My question is, what is the proper type name for these two type of connectors. I believe the second type is called edge connector but am not sure. This question arises since the first type is special because it will possibly be accessible when the PCB is in an enclosure. This is a basic requirement for the connectors of the first type.
Below is a connector that must go to the edge of the PCB:
Below is a connector that can be put anywhere:
Below is another type of thing that exists on some PCBs:
My question is quite simple. How are these differentiated? I find that second and third option are called edge connector but the first one is not.