Why do Flask rate limiting solutions use Redis?
<p>I want to rate limit my Flask API. I found 2 solutions.</p>

<ol>
<li>The <a href="https://flask-limiter.readthedocs.io/en/stable/" rel="nofollow noreferrer">Flask-Limiter</a> extension.</li>
<li>A snippet from the Flask website using Redis: <a href="http://flask.pocoo.org/snippets/70/" rel="nofollow noreferrer">http://flask.pocoo.org/snippets/70/</a></li>
</ol>

<p>What is the significance of Redis when Flask-Limiter is able to rate limit the request on the basis of remote address without Redis?</p>