Should one put labels on Previous / Next buttons?

1. What are next and previous buttons called?
2. What does button label mean?

What are next and previous buttons called?

Previous and next buttons are navigation buttons on a website, an app.

What does button label mean?

Button labels inspire the users to take an action. To indicate what a button will do, use the function as the label of the button. When users read the button labels like Save, Preview, and Publish, they know exactly what the button will do when pressed.