Outlook stores personal information in the Contacts folder.
Let's suppose that you want to enter a birthday in your calendar. You're doing this because the birthday belongs to someone you care about, right? Because it's the person who makes the date significant, it's logical to enter the birthday by starting with personal information. Outlook stores personal information as contacts. To understand how Outlook keeps track of birthdays, let's begin by looking at a contact in the Contacts folder.