A linter is a software tool that analyzes source code to identify programming errors, stylistic issues, and potential bugs. Linters help developers maintain code quality by enforcing coding standards and highlighting problematic patterns before code is executed. They can be configured to check for specific rules, such as indentation, unused variables, or naming conventions. Linters are available for many programming languages and can be integrated into development environments or automated build processes. By catching issues early, linters contribute to more reliable, readable, and maintainable code, reducing the likelihood of bugs and improving overall software quality.