Umbraco is quite similar to WordPress as a web CMS given that it has all the features you need to build and manage a website. However, it does have some advantages over WordPress, such as the additional features it comes with and the fact that a commercial entity maintains it.
However, the decision to use Umbraco over WordPress comes down to your target deployment environment. Umbraco is made to be deployed on Microsoft server architecture, while WordPress can be deployed on Apache, Windows Server, and a few other platforms.