title: Docker php: What are the :zts php images on Docker Hub
body: <p>As I was looking on: <a href="https://hub.docker.com/_/php/" rel="noreferrer">https://hub.docker.com/_/php/</a> I have seen images tagged as: <code>version_number-zts</code> or <code>version_number-zts-alpine</code> and I am wondering what does the zts indicate on these tags and how much different are from fpm or Apache images?</p>