The foremost concern of any website trying to optimize its content and structure so that Google's crawlers will discover it and assign viably high search rankings to it is discovering a valuable niche in the industry its business is competing in. Since established competition will have already laid claim to broad and industry-relevant terminology and would assuredly be the first results in SERPs generated for users who search for those terms, a smaller website's best hopes lie in capitalizing on a particular angle that the mainstream competition has not bothered to specialize in. Succeeding in this venture usually entails creating a memorable keyword that the website's brand can associate itself with more forcefully than its competitors.
To the surprise of some web designers, a website can ironically undermine its prospects for the highest positions in specific SERPs by populating all of its pages with that keyword. It would seem logical on the surface to do so, but one must remember that a given SERP on Google tends to devote one snippet per individual website. Google will naturally interpret a broad collection of web pages primarily focusing on the same keyword as a set of pages from across the website that are all competing to be the one page representing the website. It will only designate one of those pages as worthy of being the face of the snippet representing the website on the SERPs.
This is referred to as "keyword cannibalization" because one individual page on the site will end up consuming the relevance of other pages focused on its keyword by becoming the one page deemed to be the most relevant result for that keyword. To allow each of a given website's content pages its due exposure on Google, a good web designer and online marketer ultimately incorporates a different set of keywords within each page's contents because each page presumably has value existing as its own distinct entity. Various mainstream keyword-auditing tools such as Ahrefs and SEMrush contain features that showcase which pages among a website ultimately rank for the same term because of overly similar content. For more information click here https://www.reddit.com/r/SEO/comments/b9q7yt/keywordcannibalisationaudit_suggestions/.