Spotlight is the most similar to the old Directory as it’s a place where Tumblr staff highlights the best blogs in specific categories. However, unlike the old Directory, users can’t submit their favorite blogs, anymore. To get listed, you’ll have to catch the attention of the staff and get an invite. There are ways you can get your blog noticed without being on the Spotlight page, though.
The Explore page is an ever-changing list of what’s new and hot on Tumblr based on tags. If you add popular tags to your posts (appropriately, of course), they may show up on the Explore page. As Tumblr users can now browse by tag and track the tags they like most, anyone can stumble across a new blog they love. To tag posts: