Page speed measures how fast content loads on a single page. In some cases, developers will refer to page speed as page load time, which is how long it takes a page to display all its content, or time to the first byte, which is how long it takes a web browser, like Google Chrome, to receive the first byte of information from your web server.
If you’re familiar with search engine optimization (SEO), then you’ve probably heard some chatter about how page speed matters to SEO — and it does. Search engines (and users) like fast websites. That’s why search engines like Google use page speed as a ranking factor.
Adopting page speed as a ranking factor allows search engines to improve the user experience. They’re not only providing users with the information and answers they want, but with the experience they expect.