Sometimes each and every mean the same thing. Sometimes they mean almost (but not quite) the same thing.
Super helpful—we know.
For instances where you only have two items, use the word each instead of every. If you have a lot of friends, then you might have friendship bracelets covering the entire length of each arm. You are completely ambidextrous, so you can bicycle kick with each leg when you play soccer.
Once you have three things, feel free to use every. For example, you could say, "Why is every topic covered by Shmoop so thrilling?" If you want to emphasize individual items or people, though, stick to using each regardless.
The real lesson here, grammar fans, is that the word each and every are both singular, so they take a singular verb.