URL decoding, often referred to as percent decoding, is the reverse process of URL encoding. It involves translating encoded characters in a URL back into their original form. When a URL contains special characters that were previously encoded using percent encoding (e.g., spaces as %20 or ampersands as %26), URL decoding converts these encoded sequences back into their corresponding characters.

This process is essential for web servers and applications to correctly interpret and process URLs, especially when handling query parameters or form data submitted via GET requests. By converting percent-encoded sequences back to their original characters, URL decoding ensures that the data is accurately represented and can be effectively utilized by web applications.

This decoding mechanism is fundamental for maintaining the integrity and functionality of web-based interactions, allowing for seamless communication between clients and servers.