An equation is a mathematical statement that shows the equality between two expressions. It typically contains numbers, variables, and operations like addition or multiplication. For example, in the equation 2x + 3 = 7, the left side (2x + 3) is equal to the right side (7). Solving an equation means finding the value of the variable that makes both sides equal. Equations are essential in various fields, including science, engineering, and economics. They help us understand relationships and make predictions. For instance, the famous Einstein equation E=mc² relates energy (E) to mass (m) and the speed of light (c), illustrating how mass can be converted into energy.