Keywords on every webpage can be optimized and improve page ranking on search engines
keywords in HTML are words that you are targeting on a web page. They are typically short phrases that represent what the page is about. They are also, hopefully, the words that someone might type into a search engine and find your page.
In general, HTML keywords are found whether you intend them to be there or not. Keywords are just text like any other text, and when a search engine views your page, they look at the text and attempt to make a decision regarding what the page is about based on the text it
As a general rule, I would say you can optimize one page with 3 keywords or phrases. I would recommend starting with one or two. Depending on who you talk to, your percentage of keywords in your text should be between three and five percent of the total content on the site.
Choosing the Right Keywords to Optimize For is the best way to make a perfect SEO.
Lets consider an example, we have a site about dogs, do NOT try and optimize for the keyword "dog" or "dogs". Instead you could try and focus on keywords like "dog obedience training", "small dog breeds", "homemade dog food", "dog food recipes" etc. Success for very popular one-two word keywords is very difficult and often not worth the trouble, it's best to focus on less competitive highly specific keywords.
Keywords Optimization is actually based on a try and error proccess and you must start your research with easy target keywords made of three or more words.