There could be more than one answer to this question, but one possibility is "shield" meaning the drain wire for a shielded cable.
If you mean a bare copper wire, that is the "ground" wire.
The term "brown wire" refers to a specific color-coded wire used in electrical wiring. In some systems, the brown wire is designated for live or hot electrical connections.
Wire Sizing Amps
The common wire in a typical electrical circuit is the neutral wire.
The electrical terminology of a wire with no insulation on it is a bare wire.
To extend the length of an electrical wire, you can use an electrical wire extender. This device allows you to connect two wires together securely, effectively increasing the overall length of the wire.
In an electrical circuit, the black wire is typically designated as the hot wire.
In an electrical circuit, the white wire is typically designated as the neutral wire.
The black wire is typically considered the hot wire in electrical wiring.
The screw is actually only silver in color and it is where the neutral wire(s) get connected to, (white wire). the gold colored screw gets connected to the positive(black or red) wire(s). Green screw is for ground wire.
On the wire itself? It'll have the type of wire as well as the size and maybe the manufacturer part number.
Green is normally a ground wire, but without seeing the wore and how it is connected there is no way to tell for sure.