 Hiya! So in this video, we're going to look at what parallel and perpendicular lines are and how they look on a graph. And on a graph, they look like this, or like this, or even just like this. Notice how parallel lines have the same steepness. This is known as the gradient, which we will look at a lot in future videos. For now, you just need to know that parallel lines have the same gradient, go in the same direction, and will never cross each other. They will stay parallel forever. So if parallel lines always go in the same direction, perpendicular lines don't. So notice how one goes in this direction and the other one in this direction. They always cross each other at 90 degrees, which means they don't have the same gradient. They have a different steepness. Have a look around you, perpendicular lines are everywhere, like on a football pitch where the halfway line and sidelines cross each other in a car park everywhere. We will learn more about gradients in future videos, particularly of parallel and perpendicular lines, but for now, you just need to know what they look like on a graph.