These notes summarize the key concepts of order block theory for trading. The theory proposes that institutions trade using identifiable order blocks on charts. Order blocks represent price ranges where institutions are buying or selling against the retail trend. When a price breaks an order block, it will often retest the order block, allowing traders to enter. The notes explain how to identify bullish and bearish order blocks on different timeframes and how to integrate timeframes. Risk is defined as below the order block for entries. The goal is to take trades from one order block "source" or peak to the next.