Length, height, and width are all different ways of describing the size of an object. Imagine that you have a box, like a cereal box.
The length is the measurement of the box from one end to the other, like the distance from the front to the back of the box.
The height is the measurement of the box from top to bottom, like the distance from the top of the box to the bottom of the box.
The width is the measurement of the box from side to side, like the distance from one side of the box to the other.
Length, height, and width help you understand the size and shape of an object, and they're very important in many fields, like engineering, construction, and even when you're packing a suitcase for a trip. By knowing the length, height, and width of an object, you can figure out how much space it will take up and how to fit it into a specific area.