1, with different forms: Notebook is a native application that can be used on iOS devices and Mac devices, and Memo is a cloud service that can be used on iOS, macOS, iPadOS and watchOS devices, but can only be edited on iOS devices.
2. Different uses: Notes are mainly used to record personal diaries, to-do items, travel plans, etc. Memos are more suitable for recording some information that needs to be found quickly, such as meeting notes and shopping lists.
3. Synchronization methods are different: both notes and memos support multi-device synchronization, but the data of notes are stored on local devices, while memos are synchronized through iCloud.