The term __root domain__ means different things depending on if you’re talking about the Internet as a whole or about your website. Outside of the context of DNS, your root domain commonly means the highest level of hierarchy for the website you control. In casual use you can use the term domain name and __root domain__ interchangeably.
In the example below, the root domain starts at the microsoft.com node and includes everything branching from it in blue.
What is a root domain?
- raventools.com 
Technically, the root domain (or DNS root) is the highest hierarchical level of the Internet, even above top-level domains such as .com and .net. However as indicated above, outside of the context of DNS, your root domain commonly means the highest level of hierarchy for the website you control.
# See also