Google Reader aggregates RSS feeds. Adding feeds is easy, and navigating them is a joy. You can view all items, or only those from a specific website. While viewing an item (a summary of a story) in a feed, you can press j to move on to the next item, k to return to the previous item, or s to star the item. Starring is handy; it's like bookmarking, but doesn't require a toolbar, so you can use it at any computer. You can share items, too, by emailing them or putting them at a URL Google Reader provides. This URL will display all items you share. You can also embed your shared items in a blog.
Google Reader is a lens to view the Internet through. I do most of my reading on the Internet through Google Reader and find it an efficient way of browsing the news in any browser, from any computer.