What is the primary function of a digital multimeter?

The primary function of a digital multimeter is to measure voltage, current, and resistance. This multifunctional tool provides a comprehensive solution for electrical measurements, making it essential for troubleshooting and diagnosing electrical circuits.

A digital multimeter typically has the capability to switch between measuring direct voltage (DC), alternating voltage (AC), current (both AC and DC), and resistance. This versatility allows users to test different parameters without needing multiple devices, thereby streamlining the process of electrical testing.

In contrast, the options that state it measures only voltage or serves specific functions like being a power source or testing insulation resistance do not capture the full range of capabilities that a digital multimeter provides. This multifunctional use is what distinguishes it as a fundamental tool in electrical work and education.