x, y, z, w are variables commonly used in mathematics and programming to represent unknown values or data points. Each letter can stand for different quantities depending on the context. For example, in algebra, x might represent a number we need to solve for, while y and z could represent other related values. In computer science, x, y, z, and w can be used as placeholders in functions or algorithms. They help in organizing data and performing calculations. Understanding how to manipulate these variables is essential for problem-solving in both fields.