The significance of a web server in online content delivery is vital as it stores, processes, and delivers web pages to users' browsers. A web server responds to requests by transmitting HTML files, images, and other content over the internet, enabling users to access websites. Efficient web servers enhance website performance, contributing to a better user experience, faster load times, and higher search engine rankings. They serve as essential infrastructure for hosting applications, creating a seamless link between content providers and users globally.