Once the food enters your stomach, your lower esophageal sphincter keeps the food from reentering your esophagus. It then starts to release acid and other sorts of digestive juices to break down the food particles into smaller sizes. Once it's fully broken down into a size that can pass through the pyloric sphincter, which connects the stomach to the small bowel, it can empty the contents into the small bowel to continue with digestion.
Once the foodstuffs that have been processed in your stomach enter the small bowel, then the majority of digestion, nutrient, vitamin and mineral absorption occurs, as well as secretion. That's when you really start to absorb all the good parts of what you have eaten into your system.