A node is a single record of data. For example, if you were recording the GPS coordinates and bait used in a trap, 1 trap record would be 1 node.
A type defines the fields you use to record data. When you record data, you’re creating a new node, following the structure and rules you defined with the type.
A view defines what type of nodes you see, as well as how they’re sorted and filtered. You can view your data as a table or a map, views also have sorting and filters rules to hide and order your data the way you want it. For example, if you’re a real estate agent, you might have a view that only shows properties with a status of “sold”, and another view that orders the sale price of your properties from highest to lowest.
An organisation is the umbrella for all your data. You can have multiple organisations under your account, each organisation has views, types and nodes that contain all the data for that organisation.