What is server-side rendering?

Server-side rendering is the most common way to render a website. Whenever you visit a website, a request to the server is made, and it renders the website in HTML. This usually takes a few milliseconds, but it will depend on many factors, such as internet speed, location, and the number of visitors. 

If you want to visit another website, you basically perform another request to the server with the same process all over again. This can be annoying if your page has a thousand lines of code, like many of the websites do nowadays. 

However, server-side rendering is good for SEO, as the HTML page is there for robots to crawl, something that client-side rendering doesn't do well, at least not as simple as server-side rendering.