Website ranking is about your position in the search engine results for a particular keyword. Search engine optimisation is about making a Website/Web pages to rank highly (first 30 results) on the search engine results Page (SERP).
Having the correct keywords in the content of your website or blog is important for top positioning on the Search Engine Results Page (SERP). While using a proper set of keywords or phrases is essential for top positioning, it is not the only element for gaining high Search Engine Results Page positioning. There is another keyword related element search engines look for before reporting results to any given search term or query. This additional element is just as important as having proper keywords for boosting your page to the top of search engine placement but often overlooked when writing content for a site or Blog. For most relevant positioning results you should frequently use google api position check tools online.
Preponderance of Relevant Content
In the court of law sometimes a single fact is not enough to convict someone of a crime. However when there is a fact and it is backed up by other bits of related evidence then a preponderance of evidence is established. When this happens the single fact becomes much more relevant and valuable for gaining a conviction. You can think of your keywords in this same fashion. That is: a single keyword or phrase is not likely to push your page to the top of the search engine rankings but when combined with related words, your keyword or phrase becomes much more powerful and has a better chance of gaining a better SERP positioning.