The Diary is whee you keep track of everything you are doing or need to do. Each time you add a diary record, called an Event, it has a date. If you enter a time, LifeList sees it as an appointment.
If it is related to an Asset or a Contact, you select that entity from a drop down list. You can add Notes as needed. As with the other modules in LifeList, you have one Notes field for each entry, and can type whatver you want in that field. Notes are also tied back to the selected Asset or Contact, so you can go to one of those records and see any accumulated notes.