URL encoding, also known as percent encoding, is a crucial mechanism used to encode information in a Uniform Resource Identifier (URI). This process involves converting characters that are not allowed in URLs, such as spaces, punctuation marks, and non-ASCII characters, into a format that can be safely transmitted over the Internet.

By replacing these characters with a percent sign (%) followed by two hexadecimal digits representing the character's ASCII value, URL encoding ensures that the URL remains valid and can be correctly interpreted by web servers. For instance, a space character is encoded as %20, and an ampersand (&) is encoded as %26. This encoding method is essential for maintaining the integrity of URLs, especially when they include query parameters or special characters that could otherwise disrupt the URL's structure.

Proper URL encoding is vital for web developers to ensure that their applications handle URLs correctly and securely, preventing issues such as broken links or security vulnerabilities.