i want to mention to some people to perform a voltage drop test but a lot of times it can be confusing for someone who has not used an electrical meter too many times.
A meter can be used for many things from measuring voltage to resistance etc. Voltage BTW is simply the difference in electrical potential between two points. So you can measure lots of different things even when measuring dc voltage.
Here is a link to a fine explanation of a voltage drop and how to test for it.