Prefetching refers to downloading links and images in unread articles so that they're available when working offline. This powerful feature enables you to view the images and external web sites linked in your unread items even without an Internet connection.
Simply select File > Prefetch Items for Offline Reading to start prefetching your unread (and, optionally, starred) articles. Prefetching may take a few minutes if you have a lot of unread items, but it works in the background so you can continue using FeedDemon.
When you're working offline, links which haven't been prefetched have ato let you know they're not available. Clicking a link that has been prefetched shows the offline copy of the linked page.