Keyword prominence is nothing but the placement of the keywords in the article. There are many places you can show your keywords on the page so that search engines can discover them easily. Mostly the keyword is being shown in difference places of the page; for example the title of the page, URL of the page, Meta description of the page, Keyword in the starting of the article, Keyword in headings and you can also show your keyword in an Image using ALT attribute.
Keyword proximity in SEO refers to how close together keywords are to one another, or to another element on the website. There is a real art to nailing down keyword proximity within a body of text. The goal really isn’t to have all of your keywords within a close proximity, but it definitely is something to consider.
One common piece of advice you will find is that the closer your key phrase is together within a piece of content, the more relevant that page might be Googlebot for that particular keyword or key phrase.