Linked contacts

If you have multiple contact accounts on your phone (e.g. GMail, Exchange and iCloud), the Contact app on your phone will attempt to combine entries that seem to be from the same person into one entry. So, if you have Sally Ames's home number in your Gmail account, her work number in your Exchange account and her email address in your iCloud account, you would see a linked contact entry in Contacts with her home and work numbers and her email address.

If you scroll to the bottom of a contact entry in Contacts, if it's a linked contact, you'll find a link to each individual entry. If you tap the "Edit" button in the top right of a contact entry, it will bring up the edit buttons which will allow you to remove a contact from the linked contact if it's wrong or add another contact.