The Photosphere is the visible surface layer of the Sun, where light is emitted and is most commonly observed. It is approximately 400 kilometers thick and has a temperature of about 5,500 degrees Celsius. This layer is crucial for understanding solar phenomena, as it is where sunspots and solar flares occur. The photosphere emits the sunlight that reaches Earth, making it essential for life. It is also the layer from which solar radiation escapes into space. Observations of the photosphere help scientists study solar activity and its effects on the Earth's climate and space weather.