Well, a dial indicator measures in fine increments (thousands or even ten-thousandths, or the metric equivalent) by connecting a plunger to a needle on a dial. Most useful for measuring things like runout on a shaft, but many, many uses.
A bench version would be designed to sit on firmly a bench and measure things set on/clamped to that bench.
A universal version could be used to measure any number of components, rather than being designed for a specific use.
