What is Wayfair vs South Dakota?

On June 21, 2018, The United States Supreme Court ruled in Wayfair v. The State of South Dakota that states can mandate that businesses without a physical presence in a state and with more than 200 transactions or $100,000 in-state sales, collect and remit sales taxes on transactions in the state. Since the court decision, a majority of states have mandated that these and similar businesses be required to remit sales tax to the states.