Think of the Earth like a big orange - you know how an orange has lines going around it? Those lines are called latitude, and they help us know how far we are from the equator (which is the middle of the Earth).
One of those lines is called the 54th parallel north. It's a line that goes all the way around the Earth and is located about halfway between the equator and the North Pole.
If you were standing on the 54th parallel north, you would be in a place that is pretty far from the equator but not quite at the very top of the Earth. It might be a bit colder there than in places closer to the equator.
People use lines of latitude like the 54th parallel north to help them navigate and find their way around the world. It's like a big coordinate system that helps us know where we are on the Earth!