Umbraco is an open-source CMS (Content Management System), which means you get access to its source code, which is available from their GitHub repository. They also provide a framework which you can install on your own server and use in your own projects. This gives you control over your site but may not be the best fit for your specific needs. Nevertheless, Umbraco 8 has a lot going for it – and there are lots of reasons why people choose it over WordPress.
Wordpress on the other hand, is a platform specially designed for building blogs, wikis, and websites. It has tons of features, especially when setting up themes (themes are what you can use to decorate your site), but it’s not as configurable as Umbraco.
Wordpress is the most popular platform for building websites. It has become so popular that some professionals have begun to suggest that WordPress is “the web” (or even “the world”). However, it does not come with some of the features other platforms do. Perhaps most importantly, it does not support content management systems (a common feature of rich internet applications like Wordpress), and therefore it is usually seen as more difficult to get set up than other platforms like Umbraco.
When you do manage to set up a WordPress site, you will find yourself spending much more effort maintaining it than sites built with tools like Umbraco or Drupal, because there just aren’t quite as many plugins available for all the things people need on their sites, such as embeddable content blocks, social media plugins and even custom themes.