Amphoteric substances can behave as acids or as bases depending upon their surroundings. So aluminium hydroxide in reaction with acids will behave as a base
and in reaction with bases it will act as an acid
Generalic, Eni. "Amphoteric substances." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
Glossary
Periodic Table