Introduction to Components for Altium

Symbol vs Footprint vs Component

With a software as complicated as Altium and the circuit design field in general, there is a lot of terminology that might be confusing to newcomers. Hopefully, this section will be able to clarify some of that.

The three most important terms to know when creating a part in Altium are the symbol, footprint, and component. Each one of these plays an integral role in part creation, and you will need to become familiar with what each one means. In short, a symbol is the part that appears on your schematic, a footprint is the part that appears on your PCB layout (includes pads, markings, 3D body), and a component is what combines the symbol and footprint into a part for use and also includes other data like parameters, datasheets, and supplier information. 

Most of the time with ICs a symbol will not map 1-to-1 with a footprint, so extra care needs to be taken that everything is mapped correctly according to the datasheet of the component you are trying to make. The below graphic visually shows the difference between a symbol and footprint.

Component Creation Screen: