HTML has 5 different tags to preload something. Here’s a deep-dive into all

For Chrome, see the full table of Chrome priorities for more details

asks the browser to download and cache a resource (like, a script or a stylesheet) in the background. A browser has to set up a connection when it retrieves something from a new third-party domain. will help you when you have some important resources on third-party domains the browser doesn’t know about in advance.

Source: 3perf.com