Balance scales are simple tools used to measure weight by comparing two objects. They consist of a horizontal beam supported at its center, with two pans hanging from either end. When an object is placed in one pan, the scale tips until the weights in both pans are equal, allowing us to determine the weight of the object. This method of measurement is based on the principle of equilibrium. These scales have been used for centuries, dating back to ancient civilizations like the Egyptians and Greeks. They are still relevant today in various fields, including science, cooking, and commerce, helping us ensure accurate measurements in everyday tasks.