Where is best adding Heading Tag Image with alt tag OR Content?

I am some confuse for adding H2 & H3 tag. Where I can add h2 & h3 tag on content or Images with alt tag? which one will be good for SE ranking?

 

Here is an image to help you understand how to include your Heading tags. For your images, save the file name as your keywords. If you have many keywords, separate them with hyphens (-). Hyphens are known by search engines as word separators. Another thing is to give your image a title also containing keywords. Adding an alt tag to your image also helps for your images optimization, and that's about all you could to optimize your website's images.

 

Thanks for explain by image.

 

My pleasure, if you ever have more questions, don't be shy to ask!