For me, the Encyclopedia Britannica fills a large gap between 1.) dictionaries and quickly looking something up on google, and 2.) subject-specific books. For example, articles about major topics such as "Ancient Egypt", "Buddhism", "Economic Development", "Mozart", "Paris", "The Moon" are generally 10-50 pages in length and a good starting point to learn about a topic of interest without having to purchase a specialized book (which is often more detailed than desired).
Compared to Wikipedia, I found that for the same amount of reading time I get more useful information out of the Encyclopedia Britannica; the articles are on average better written (see, for example, "Money" by Milton Friedman, or "Space-Time" by Albert Einstein), and less reflective of authors' personal interests. I still use Wikipedia quite a bit for looking up specialized topics (such as the history of the C programming language, or a pop musician), but for general topics the EB is my favorite starting point.