Final answer:
The visible layer of the Sun that we normally see is the photosphere, which is where the Sun becomes opaque, blocking deeper views.
Step-by-step explanation:
The layer of the Sun that we normally see is called the photosphere. The photosphere is analogous to an opaque barrier similar to how smog may prevent us from seeing through the Earth's atmosphere on a smoggy day. This layer marks the point past which we can't see deeper into the Sun. While the outer atmosphere of the Sun is transparent, allowing us to look a short distance through it, the photosphere is where the Sun becomes opaque. If we could view the Sun beyond the photosphere, we would see other layers such as the chromosphere and the corona, the latter of which is only clearly visible during a total solar eclipse. The photosphere's temperature is about 5800 K, while sunspots on the photosphere are cooler, with temperatures around 3800 K.