A voltage tester is a simple electrical tool used to check the presence of voltage in a circuit or device. It helps ensure safety by indicating whether wires or outlets are live before working on them. There are various types of voltage testers, including non-contact voltage testers and multimeters, each designed for specific applications. Using a voltage tester is straightforward. The user places the tester's probes on the electrical component being tested. If voltage is present, the tester will light up or beep, providing a clear indication. This tool is essential for electricians and DIY enthusiasts to prevent electrical accidents.