In 2020, trillions of dollars flooded ESG funds, and many analysts are expecting this trend to continue in 2021. BlackRock, the largest asset manager in the world, plans to have $1.2 trillion in ESG assets in the next 10 years, and an estimated one-third of all U.S. assets under management are already sustainably invested.  Given the importance of ESG to the securities markets, we herein present an elementary primer, explaining ESG issues and how they are affecting companies and their public disclosures—your ABC’s of ESG, so to speak.