Okay kiddo, have you ever heard of a place called Fort Henry? It's in Kingston, Ontario and it's very special because it used to be a military fort a long time ago. Now, people can visit Fort Henry and learn about what life was like for soldiers who lived there.
One of the things you might see when you visit Fort Henry is something called the Fort Henry Guard. These are soldiers who dress up in special uniforms that look like the ones from a long time ago. They use guns that don't have real bullets in them, so they're very safe.
The Fort Henry Guard soldiers stand really still for a long time, which can be hard to do! They're called "sentinels" and their job is to stand guard and protect Fort Henry. They also do special marches and drills that are really impressive to watch.
So, in summary, the Fort Henry Guard are soldiers at Fort Henry who dress up in uniforms and protect the fort. They do some really cool marching and are very good at standing still for a long time.