WordPress is a open-source content management system which is mainly build in PHP and used with MySQL or MariaDB database servers for store data in database.
It was designed and introduced as a blogging plateform but now a day it is not limited to blogging but it also used for large website development like ecommerce or other company sites.
WordPress makes easy to use cms as there are many ready made plugins and themes which help to make things very simple by followin simple steps and in very low clicks.
There is not required very detail technical knowledge for creating website in wordpress, even non-technical person can create website in very easy few steps.