A "terminal" or "terminus" means the "end"s of a circuit component (wires, resistors, capacitors, ICs, etc.). According to their shapes, termini are known as lead, leg, screw, pin, plug, probe, contacts, etc. On a terminus we apply electrical connectors.
A "terminal" means the place in a circuit component where the component physically "ends" and some other circuit component connects.
A terminal is the same as an electrode, but is used in more mechanical sense, whereas the term electrode is used in a much more conceptual and electronic sense.
The terminals may be flexible or rigid. According to shape, rigidity, etc. it is called many other things like lead, leg, pin, screw, plug, probe (in meters), contact (in line testers), nub (in batteries), etc.
On the termini of a part the counterpart attaches with a definite type of electrical connection like soldering, easily removable mechanical fasteners like screws, plug-and-socket mechanism, crocodile clips, holders, spring (battery case), or even sometimes physically knotting or fastening or winding to wire terminals in a specific way, or fastening a wire through a hole or eye in the leg of a component, or sometimes using PVC-tape or paper-masking-tapes.
For a component, the term pin-out is used to indicate the spatial arrangement pattern of the termini of a specific nature.
Examples:
1-terminal component: whip antenna.
2-terminal component with no polarity specifications: resistors, non-electrolytic capacitors.
2-terminal component with polarity-specification: electrolytic capacitor, diode.
3-terminal component: potentiometer, transistor, some mobile batteries, some piezo crystals (some piezo crystals are 2-terminal), etc.
More than 3 terminals: ICs (integrated circuits; they also occur with 3 or less pins), some mobile batteries.
