An e-diary is an electronic calendar that allows users to schedule, view, and store appointments and events. Some advantages of an e-diary are that it can help prevent double-booking, allow reminders to be set for upcoming appointments, and enable diaries to be shared with others. The document provides instructions on how to access and create an e-diary using Microsoft Outlook. Students are tasked with creating an e-diary scheduling their classes, appointments, and plans for the rest of the week.