Okay kiddo, so imagine a really long time ago, there was a whole bunch of people living in a place called Egypt. These people thought it was really important to have someone in charge of them, to make sure they were safe and had everything they needed.
So they came up with something called a dynasty. A dynasty is kind of like a really big family, where the oldest person in the family is in charge and makes all the important decisions.
In ancient Egypt, there were many different dynasties over a long, long time. Each dynasty had a different person in charge, but they were all related to each other like cousins or siblings. The person in charge was called a pharaoh, which means "great house" in their language.
Whenever a new pharaoh came into power, they would start a new dynasty. This would happen when the old pharaoh died or when they were overthrown by someone else.
Each dynasty was known for different things, like building big pyramids or creating stunning artwork. But they all had one thing in common: they were all very important to the people of Egypt.
So basically, a dynasty is like a really big family where the leader is in charge, and in ancient Egypt, they had lots of these dynasties over a long time.