What interactions can happen between two populations in a community

The answer is Neutralism, amensalism, commensalism, mutualism, and competition.

Neutralism is the most common type of interactions between populations in which neither population affects the other one.

Amensalism is a relationship between two population in which only one of them suffers, and the other one is not affected.

Commensalism is a relationship between two population in which only one of them has benefit, and the other one is not affected.

Mutualism is a relationship between two different populations in which both species benefit.

Competition is an interaction between populations in which they compete for limited resources.