Should you aim for the singular or the plural keyword? Well, this depends on the query. As Google is learning more about search intent of your query, it is able to better guess what you’re looking for. For instance, if you search for book, you get a different result than if you search for books. Apparently Google thinks that in the first case you’re looking for a definition or certain stories, in the second case it believes you’re looking for books to buy. So make sure you know what you offer on your page and that it fits with the query and results Google gives on that query.
Simply put, search engine optimization (SEO) is the process of optimizing the content, technical set-up, and reach of your website so that your pages appear at the top of a search engine result for a specific set of keyword terms. Ultimately, the goal is to attract visitors to your website when they search for products, services, or information related to your business.