Question: Two organisms living together for their mutual benefit?
Disambiguated questions and answers: question: What is it called when two organisms living close together, long term for their mutual benefit?
What is it called when two organisms living together, not necessarily long term, experience net benefit?
What is the evolutionary process called when two organisms living together work or act together for mutual benefits?
answer: Symbiosis
Mutualism
Co-operation
Natural Questions answer: Symbiosis (from the Wikipedia article "Symbiosis")