A task is something that you need to accomplish that will go away once completed ...something that you are going to start and then finish.
For instance, a task might be a reminder to call someone, to schedule a follow-up appointment, or even to go pick up your laundry. All JobScore users can assign tasks to each other. All Tasks have a due date, and can be completed, deleted, edited and re-assigned.
Notes are information that you don't want to lose about a candidate...they are more permanent, and are always connected to specific candidate records. If there's something you want to remember about a candidate or have other people know, add it as a note.
You can also attach documents to notes, so you can store and share employment applications, engineering code samples or artwork within notes.