A wire connects elements. In the editor a wire is represented by a multi-segmented line. This line may represent a single wire carrying a single boolean value (or "neither" for wires connected to the outputs of tri-state devices). A single line may also represent a bundle of two or more wires.
A wire can have one or more segments and can branch out to connect many elements. Wires cannot, however, contain a loop. That is, starting at any place on a wire, you should not be able to follow segments of the wire from place to place and then return to your staring place. JLS will not let you connect a wire with a loop.
Click here to see how to create wires.
You can easily find out how many wires (bits) a given line represents by moving the cursor over the line and checking the information shown in the blue message bar above the circuit. If the wire is not yet connected to anything it will not know how many bits it represents. Once connected to something, it will tell you how many bits there are. If the wire is not yet connected to the output of any element, then it will tell you so.
When pointing at a wire you will also be told the current value on that wire. This will be 0 before any simulation has been done. It will be the current value while stepping the simulation, or the final value after simulation completes. The final value will remain even if you make changes to the circuit.
The current value will be shown in three ways. The first is as a hexadecimal value, then in parenthesis as an unsigned integer (base 10) and a signed (2's complement) integer (base 10). For example, an eight-bit wire bundle with hex value 0xf9 will be shown as:
Wires will appear red when their current value is non-zero, black when their current value is zero.