A voltage tester is a simple electrical tool used to determine the presence of voltage in a circuit or device. It helps ensure safety by allowing users to check if wires or outlets are live before working on them. Voltage testers come in various forms, including non-contact testers, which detect voltage without touching the wire, and contact testers, which require direct contact with the electrical source. These devices are essential for electricians and DIY enthusiasts alike, as they help prevent electrical shocks and accidents. Using a voltage tester is a straightforward process, making it an important tool for anyone working with electricity.