Lazy loading is a web development technique that is used to load the images and videos only when the user is about to view them. In other cases, the entire website is first loaded. With lazy loading, the page loads faster, reducing the initial data that is spent for the website to load.
Lazy loading is crucial to reduce the bandwidth usage and increase the website performance. It increases the SEO by decreasing the load time of the page. Many search engines consider this facter to rank the website.