The Department of State announced that certain individuals and entities have been added to the Department of Treasury's Specially Designated Nationals and Blocked Persons (SDN) List due to their connection with Iran. This action blocks their property and interests within U.S. jurisdiction and prevents U.S. citizens from engaging in transactions with them. Notably, a Chinese company, Huaying Huizhou Daya Bay Petrochemical Terminal Storage Co., Ltd, is being sanctioned for engaging in significant transactions related to Iranian petroleum.
Simple Explanation
The U.S. Government is stopping some people and a Chinese company from doing business in the U.S. because they did big money deals with Iran, which they shouldn't have done. This means their stuff in the U.S. is frozen, and Americans can't buy or sell things with them.