When you’re working in SharePoint and you have to fill in someone’s name, you’re seeing what is commonly called a People Picker field. It’s a field that’s set up to allow for names, and it has two icons to check the name format as well as to look up a name in the Select People and Groups dialog box.
However, I often see people clicking on the Address Book icon even if they know the name of the person they want to add to the field. Following are some various ways to add a person’s name into the field and maybe save yourself some clicking around to do so.