CW Complex

A CW complex is a mathematical structure used in topology, a branch of mathematics. It combines two ideas: "cells" and "gluing." Think of cells as basic building blocks, like points (0-dimensional), lines (1-dimensional), surfaces (2-dimensional), and higher dimensions. These cells are arranged or "glued" together in a certain way to form a more complex shape. This method allows mathematicians to study the properties of spaces, like their shape and connectivity, in a systematic manner, making it easier to analyze and understand complex topological structures.