Okay, so imagine you have a bunch of cones like the ones you see at a construction site. Now, let's say you only want to look at cones that are "open" at the top, so you can see through to the other side. We'll call these cones "convex cones."
But what makes a cone "convex?" Well, imagine taking a flashlight and shining it inside the cone. If you can see the flashlight beam from every point inside the cone, then the cone is convex. This means that no matter where you are inside the cone, you can always shine your flashlight through to the other side.
Convex cones are important because they have really cool properties. For example, if you take any two points inside a convex cone, and draw a line between them, that line will always stay inside the cone. This means that convex cones are great for all kinds of math and science problems!
So next time you see a construction cone, remember that there are special cones called "convex cones" that are even cooler!