contact, crimp terminal, pin, socket, receptacle, blade, tab
The terminal is where the connection is actually made, and where most field failures start. Four attributes decide whether the part in your hand is the right one.
Family and size. A terminal only fits the cavity it was designed for: TE MQS 0.63, AMP Superseal 1.5, Aptiv Metri-Pack 280, Molex MX150, Sumitomo TS 090. The number generally refers to the mating tab width in millimetres, not the wire size.
Gender. Pin, sometimes called male, tab or blade, mates with a socket, sometimes called female or receptacle. Housings are usually sold as matched plug and header pairs, and the terminal gender follows the housing, not the wire.
Wire range. Every terminal has a validated conductor cross-section window and an insulation diameter window. Crimping outside it gives a joint that passes a pull test on the bench and opens under vibration.
Plating. Tin is the default for most automotive signal and power circuits. Gold is used on low-level signal circuits, safety-critical circuits, and connections that see repeated mating. Tin and gold should not be mated to each other in a permanent connection: the pairing accelerates fretting corrosion. This is one of the most common substitution errors when a buyer accepts "the same terminal, different suffix" under time pressure.
Terminals are also where quantity bites. A single harness variant can consume tens of thousands, so a shortage on one terminal reference stops a line as surely as a shortage on a control module.
Harness Code sources terminals against the housing they have to serve, and states plating and wire range explicitly on any alternative it proposes.
Related terms
Connector housing
A connector housing is the moulded plastic body that holds and positions the terminals of an automotive connector. It is sold separately from the terminals and seals it accepts, so a working connection is always a matched set of housing, terminal and seal, not a single part number.
Wire seal and cavity plug
A wire seal is a rubber grommet crimped with the terminal that seals the gap between the wire and the connector cavity. A cavity plug seals an unused cavity. Together they give a sealed connector its rated ingress protection; a single missing seal voids it.
Counterfeit risk and verified sourcing channels
Counterfeit risk is the risk of receiving fake, re-labelled, recycled or out-of-specification components presented as genuine. It rises sharply for parts that are scarce, obsolete or on allocation, which is exactly when buyers are forced outside their usual channels.