Difference between SAP notes

In SAP’s terminology there is a differentiation between types of SAP notes (following text is extract from SAP Service Marketplace (OSS) + my comments):

SAP Notes help you to avoid and correct errors in the SAP system. The SAP Note Search provides fast and easy access to those SAP Notes relevant for you. This is your first help when you facing any problem with your SAP system. Accessible via OSS quick link service.sap.com/notes

SAP HotNews are priority 1 (very high priority) SAP Notes. They tell you how to resolve or avoid problems that can cause the SAP system to shut down or lose data. If you are potentially affected by these problems, you must ensure that you read SAP HotNews. Always check this out; you never know if there are not any side effects caused by note implementation. You can personalize and can subscribe to SAP HotNews in the SAP Service Marketplace Newsletter. Accessible via OSS quick link service.sap.com/hotnews

SAP TopNotes are the most important notes of a component or a subcomponent reported on successfully closed customer support messages. The 10 most successful notes are selected on a monthly basis in a semiautomatic process. You can also personalize SAP TopNotes, and choose to be notified by the SAP Service Marketplace Newsletter about new SAP TopNotes available. It can happen that customer message created by you will follow up to SAP note and you receive TopNotes notification to implement some note that you already have because you were very first customer that faced error related to this note. Accessible via OSS quick link service.sap.com/topnotes