A staple in web dev interview questions, be prepared to answer this one. Progressive rendering is a technique that is used to render content for display as quickly as possible. Here, small parts of a website are updated sequentially on the server and streamed to the client in parts instead of waiting for the whole page to be rendered. Once the critical content is rendered on the server, it is streamed to the client without waiting for non-critical content, which is streamed later. The browser progressively renders the HTML on the web page as soon as it receives a chunk of the critical content. As and when the non-critical chunks are received from the server, they are rendered on the web page.