ESG investing, also sometimes called sustainable investing, channels money into companies that meet environmental, social, and governance guidelines. ESG investing can be either active ESG investing or passive ESG investing. Active ESG strategies include becoming part owner in a sustainable company, such as a clean energy company.Passive ESG investing is more accessible to small investors like me. Passive ESG strategies involve investing in funds or building a portfolio of small ESG investments. Investing in the best ESG funds ensures that I will reap good returns, avoid excessive fees, and support responsible corporate behavior.