The acronym "HTTP" stands for Hypertext Transfer Protocol. It is the foundational protocol used for transmitting data on the World Wide Web. HTTP governs how messages are formatted and transmitted between clients and servers, allowing users to access web pages and resources. Additionally, it establishes rules for web browsers and servers to communicate effectively. An upgrade of HTTP, known as HTTPS (Hypertext Transfer Protocol Secure), incorporates encryption for secure communications, enhancing data protection during online transactions.