Phone Number Field
The Phone Number Field accepts any text, since phone numbers vary greatly globally. The Phone Field is most useful when it's necessary to easily identify phone number data within the app or app templates.
Data will be stored as simple text with the phone number that was entered on the content entry form.
If identification is not a concern, then consider using a simple text field for your project.
Content Entry Form
This field may be set to repeatable during field creation to collect more than one phone number at a time.