The associated video is here
Firebase App Backend - The Firebase application that you made on the website https://www.firebase.com/account/#/
Firebase Database - This entire JSON object which is part of the Firebase app backend.
Key - A node name or key in Firebase. It is on the left of it's value.
List, Map, Collection - A key/value pair that has multiple children.
Location - URL location of a node in the Firebase database.
Node - A specific location that has a key/value pair.
Object - A key value pair that represents a key and all the data in an analogous Java object.
Property - A key/value pair that holds a single value.
Root Node - The top level node of a Firebase database. Its' location will be your base Firebase URL (the url you see when you first click on your Firebase App Backend).
Value - The actual value of a certain location in the Firebase database. This can be a string, number, boolean or a Firebase object.