I just had a look into the blog skeleton which uses antimatter theme. I noticed that some template files uses "extends" and other do use "embed". For example item.html.twig uses:
{% embed 'partials/base.html.twig' %}
…{% endembed %}
I changed it to:
{% extends 'partials/base.html.twig' %}
and couldn't see any difference. It works as before.
So could anyone tell me whats the difference between those two and when use to which?