QUOTE: “As the Googlebot does not see [the text in the] the images directly, we generally concentrate on the information provided in the “alt” attribute. Feel free to supplement the “alt” attribute with “title” and other attributes if they provide value to your users! So for example, if you have an image of a puppy (these seem popular at the moment ) playing with a ball, you could use something like “My puppy Betsy playing with a bowling ball” as the alt-attribute for the image. If you also have a link around the image, pointing a large version of the same photo, you could use “View this image in high-resolution” as the title attribute for the link.”
A variety of methods can increase the prominence of a webpage within the search results. Cross linking between pages of the same website to provide more links to important pages may improve its visibility. Writing content that includes frequently searched keyword phrase, so as to be relevant to a wide variety of search queries will tend to increase traffic. Updating content so as to keep search engines crawling back frequently can give additional weight to a site. Adding relevant keywords to a web page's metadata, including the title tag and meta description, will tend to improve the relevancy of a site's search listings, thus increasing traffic. URL canonicalization of web pages accessible via multiple URLs, using the canonical link element or via 301 redirects can help make sure links to different versions of the URL all count towards the page's link popularity score.
QUOTE: “So if you have different parts of your website and they’re on different subdomains that’s that’s perfectly fine that’s totally up to you and the way people link across these different subdomains is really up to you I guess one of the tricky aspects there is that we try to figure out what belongs to a website and to treat that more as a single website and sometimes things on separate subdomains are like a single website and sometimes they’re more like separate websites for example on on blogger all of the subdomains are essentially completely separate websites they’re not related to each other on the other hand other websites might have different subdomains and they just use them for different parts of the same thing so maybe for different country versions maybe for different language versions all of that is completely normal.” John Mueller 2017
Ideally, you will have unique pages, with unique page titles and unique page meta descriptions . Google does not seem to use the meta description when ranking your page for specific keyword searches if not relevant and unless you are careful if you might end up just giving spammers free original text for their site and not yours once they scrape your descriptions and put the text in main content on their site. I don’t worry about meta keywords these days as Google and Bing say they either ignore them or use them as spam signals.