Here's a breakdown:

* Acid: An amphoteric compound can donate a proton (H+) to a base.

* Base: An amphoteric compound can accept a proton (H+) from an acid.

Examples of amphoteric compounds:

* Water (H₂O):

* As an acid: H₂O ⇌ H+ + OH-

* As a base: H₂O + H+ ⇌ H₃O+

* Aluminum hydroxide (Al(OH)₃):

* As an acid: Al(OH)₃ + 3H+ ⇌ Al³+ + 3H₂O

* As a base: Al(OH)₃ + OH- ⇌ [Al(OH)₄]-

Let me know if you'd like more detailed explanations or examples!