Tim Berners-Lee invented the World Wide Web in 1989-1990 at CERN as a system for sharing text and graphics over the internet. It used HTML for formatting pages and HTTP for transferring data between clients and servers. The graphical Mosaic browser in 1994 made the web widely popular, fueling its exponential growth. The core components that powered this growth were clients, servers, HTTP, HTML and URIs for identifying web resources.