PCB, printed circuit board is a thin board made of fiberglass, composite epoxy, or other laminate material.
A Multi-Layer PCB is a PCB that has more than two layers.
FR4 is a sign for rating flame resistant material. It specifies that resin material is capable of automatically extinguishing when it is in a flame state.
HDI, a short form for high density interconnector, is a type of technology for PCB fabrication. It depends on micro blind via technology to manufacture PCBs with traces organized with high density.
Gold fingers are connectors on the edge of a PCB after gold plating. They have to be hard, smooth, and flat, behave excellently as a conductor
External layer of PCB, also called outer layer, is an outer copper layer where components are attached to.
Cutout refers to a groove that is dug on a PCB.
Chip on board is a type of bare chip SMT technology by directly mounting chip on a PCB.
PCB house is the factory fabricates PCB.