Volts
The volt.
The unit of electric flux is Volt-meter or Newton-meter^2 Coulomb^-1.
Electric flux.
All voltage reading are usually read with a volt meter. This volt meter can be a hand held unit like electricians use.
The unit for electric potential difference is the volt (V).
A metre is the basic SI unit of length, but is often misspelt as 'meter'. A meter might refer to either a measuring device, e.g. a Volt meter measures the energy possesed by the current in a current in a circuit.
The rate of change of potential with respect to distance is called potential gradient. its unit is volt per meter or newton/coulomb.
The Volt
Not "Volt" - but "Volta". The unit "volt" was named Alessandro Volta.
The unit of current is the ampere. The unit of potential difference, or electromagnetic force is the volt.
Parallel
It depends on what you want to monitor. Most commonly the volt meter is connected in parallel with the battery or the alternator.