Use of the alt text and description attributes of the image. And you can use image sitemap also.

According to the web masters xml sitemap is the important on page seo aspect. If you have a sitemap Google easily crawl your website.

We can promote the website locally by the use of the local seo. And we can promote the website all over the world, we can target the people in all over the world.

Google is best search engine than others because most of the people in a world search on the Google.