comparator

1. Any of various devices for comparing a physical property of two objects, or an object with a standard.

   optical comparator

   Komparator

2. An electronic device that compares two voltages, currents or streams of data.

   electrical comparator

   digital comparator

3. Anything that serves as a comparison.

4. A thing being compared against in the PICO process; often, a diagnostic method or a treatment being compared against another.

5. An application or program that compares prices, rates, tariffs of flights, smartphones, cars, etc.

regular