Photosphere - it is the Sun’s deepest layer, and the layer visible to human eyes directly from the Earth. It is also called the solar surface
Chromosphere - This layer of the Sun is located between 250 miles and 1300 miles above the photosphere. The chromosphere has temperatures around 4000K at the base, and 8000K at the top.
Transition Region - This layer is very thin with a size of about 60 miles, and it is present between corona and the chromosphere.
Corona - This layer is the Sun’s outermost layer. It starts at roughly 1300 miles over the photosphere and it has no upper limit. Its temperature is between 500,000 K to 1 million K.
