General Caption: The solar structure (i.e., the structure of the Sun) shown in two cutaway diagrams.

Image 1 Caption: Features:

1. Solar core: This is where hydrogen burning occurs primarily by the Proton-proton chain (PP chain).
2. Radiative zone: This includes the solar core and is where energy is transported by primarily by radiative transfer.
3. Solar photosphere: This is where electromagnetic radiation (EMR) primarily escapes from the Sun. It is the 1st main region of the Sun's atmosphere.
4. Solar temperature minimum: Just above the solar photosphere and just in the chromosphere, the solar temperature reaches a minimum of ∼ 4100 K. Both inward and outward from this point, the temperature increases.
5. Chromosphere: It is the 2nd main region of the Sun's atmosphere.
6. Solar transition region: the transition region going outward between chromosphere and corona.
7. Corona: It is the 3rd main region of the Sun's atmosphere.
8. Solar wind: The 4th main region of the Sun's atmosphere in a sense. The solar wind extends to the heliopause at ∼ 120 AU where the interstellar medium (ISM) begins.
9. Smaller scale sturctures: flares, granules, prominences, sunspots (with sunspot umbra and sunspot penumbra).
10. The diagram is a cartoon, but the outside part is probably close to a real image in false-color.
11. I think the outer part represents an image in the extreme ultraviolet. For comparison, see the extreme ultraviolet, false-color Sun image The Sun by the Atmospheric Imaging Assembly of NASA's Solar Dynamics Observatory.

Image 2 Caption:Features:

1. A diagram of a solar type star or G2 V star.

2. As one can see stars have no sharply defined surface.

   There is just a gradual transition from dense opaque regions to relatively transparent outer region that extents into stellar wind in all cases it seems???.

3. The main layer of transition from opaque to transparent is the stellar photosphere which is what one usually means when one says the surface of a star.

4. For a longer discussion of this image and the stellar photosphere, see file star_g2_v.html.

Images:

1. Credit/Permission: © User:Kelvinsong, 2012 / Creative Commons CC BY-SA 3.0.
   Image link: Wikipedia: File:Sun poster.svg.
   
2. Credit/Permission: Project leader: Dr. Jim Lochner; Curator: Meredith Gibb; Responsible NASA Official:Phil Newman, 2006 / Public domain.
   Image link: Wikipedia: File:Sun parts big.jpg.