Why do nations perform alliances, and what are some examples of different kinds of alliances along with an explanation of their purposes

Well many people make alliances for a common goal and or a mutual agreement of profit such as ww2 the allies Great Britain and the United States along side with the soviets and France working together to take out hitler and his army

Answermost of the time it would be ground into fine sediment,and sometimes they are carried away from the original location;