Link prefetching allows web browsers to pre-load resources.
Resources which can be prefetched include: JavaScript, CSS, image, audio, video, and web fonts.
Plain hyperlinks (which almost universally result in GET requests) are often used to implement logout functionality and account verification, e.g., when a user completes an account creation form, and an automated service sends a verification e-mail to the user's given e-mail address.
[14] Additionally, there are a number of criticisms regarding the privacy and resource usage implications of link prefetching: In the case of mobile devices or for users with a limited bandwidth allowance, prefetching may result in an unnecessary costly drain on limited bandwidth.
In the case of prerendering, Google warns that improper use may result in the aforementioned increased bandwidth usage, slower loading of other links, and slightly stale content.