'Test-Driven Development (TDD)' is a software development methodology focused on short, repetitive development cycles: transforming requirements into specific test cases, followed by software improvement to ensure these tests are passed.

The process begins with writing an automated test case that fails, outlining an intended enhancement or function. Developers then write minimal code to pass this test and refactor this code to meet quality standards. TDD promotes simplicity and fosters confidence in the software.

A key benefit of TDD is early bug detection, which reduces the time and cost of later fixes. It leads to well-structured and testable codebases, as test writing requires thoughtful design consideration.

While TDD is lauded for its focus on essential code and bug minimization, it has its critiques, such as the potential overemphasis on unit testing and the time investment required for effective implementation.

Conclusively, Test-Driven Development is an integral practice in modern software engineering, advocating for clean, efficient, and error-free code. It's a fundamental aspect of Agile methodologies and is widely implemented for its substantial impact on software quality and maintainability.