The Open Water Diver program is a mix of theory sessions, confined water sessions (shallow, calm water similar to a swimming pool), and open water sessions (deeper than 5 meters/16 feet).
You will learn important rules of dive safety, how to dive independently by checking your own air etc., and valuable practical skills such as how to hover neutrally buoyant in the water.
There are some exquisite spots for scuba diving on our beautiful planet. Here are: The 9 Best Scuba Destinations for Year-Round Diving.