Unless you are reading this document in the form of PDF, or on printed paper, chances are that you are already using Authorea to read this document. In that case, refer to the 'bread crumb' or the top of this document and you will see this bar. If you will note, this bar has the following elements (more or less, from left to right):
That's a lot. But those are the ones you will need for writing a document for academic purposes. This is purpose fit to allow you with a set of features that you will use for authoring academic documents. Compared to that layout, check out what happens when you use a standard word processing app (here we will see a Microsoft Word document toolbar):