This heading and text is part of an HTML Module. You can use it to add descriptive text or an introduction to the page. Alternatively, you can simply delete it if the CMIS Module content and layout is sufficient.
To edit the titles of this and other modules you must be logged in with a user who belongs to the CMIS Administrator role. Hover over a title until an edit icon appears (a pencil: 
) and click it. Change the title as required. When finished hover over your changed text and click the update icon (a disk: 
).