The note is a piece of plain text recorded within Epic's database. Each note records its author and when it was created. Records that can have notes attached (such as companies and projects) display their notes in reverse chronological order.
Notes are stored within Epic's database. This means that notes' content can be searched.
Epic ensures that only one note is created per user per day per record. If you create a note and then edit it later on the same day then a single note is recorded. If you come back the next day, a new note record is created.