A smile is a simple yet powerful expression that shows happiness or friendliness. When someone smiles, their lips curve upward, often revealing their teeth. This gesture can brighten a person's day and create a warm atmosphere. Smiles are universal; they can be seen in people of all ages, from babies to grandparents, and are often contagious, making others want to smile back. Smiling can also have positive effects on our health. It releases endorphins, which are chemicals in the brain that promote feelings of joy and reduce stress. Even when we don't feel happy, forcing a smile can trick our brain into feeling better. So, a smile is not just a reflection of joy; it can also create joy!