Google Keywords is a tool used to optimise relevant website content so that it corresponds with user search terms. In addition to writing interesting and engaging copy, keywords need to be adhered to somewhat so that Google can order your website within its search parameters.
Keywords are either singular words or phrases and are either commonly [high search volume/competition] or rarely [low search volume/competition] searched for in Google.
In order for keywords to be constructively used within content there needs to be thought of what potential customers are searching for. Which purchasing audience does your website want to attract? Once you find this audience and their relevant keyword searches, content can be structured advantageously.
However, specificity is important here as being overly specific with regards to phrasing will end up in too few search leads, while having overly general keywords will result in your website getting lost in the masses. Find keywords that are high in terms of search volume but low in competition and then integrate these strategically within website content. This results in more effective and cost-efficient SEO.