FRESS improved on HES's capabilities in many ways. FRESS users could insert a marker at any location within a text document and link the markered selection to any other point either in the same document or a different document.
FRESS had two types of links: tags and "jumps". Tags were one-way links to information such as references or footnootes, while jumps were two-way links that could take the user through many separate but related documents, much like the World Wide Web of today. FRESS also had the ability to assign keywords to links to assist with navigation. FRESS is also possibly the first computer-based system to have an "undo" feature for quickly correcting small editing or navigational mistakes.
FRESS was essentially a text-based system, and unlike the modern Web, editing links was a fairly complex task. FRESS also provided no method of knowing where the user was within a collection ("web") of documents, which could prove somewhat disorienting.