Symmetry breaking is a concept in physics and mathematics where a system that is initially symmetrical becomes asymmetrical. Imagine a perfectly balanced seesaw; if one side is pushed down, the balance is disrupted, leading to a new, uneven state. This phenomenon can be observed in various fields, such as in the formation of crystals or the behavior of particles in the Standard Model of particle physics. In nature, symmetry breaking helps explain why certain particles have mass and why the universe has distinct structures. For example, during the Big Bang, the universe started in a symmetrical state, but as it expanded and cooled, it underwent symmetry breaking, leading to the diverse forms of matter we see today.