Content Optimization is a concept that maximizes a single page's ability to draw traffic. After you're comfortable with keyword research and have chosen several keyword phrases, it's time to develop content around those keyword phrases.
In keeping with the landscape company example (see the Keyword Research section of this site), it may not be reasonable to think that your entire site can be optimized for a keyword phrase like "landscaping services atlanta". We can use that across a bunch of pages but at least one page should be optimized for that single keyword phrase. Answer questions like, "Why should I choose you to be my landscaping services (provider) in the Atlanta area?
Using optimized content to target specific keyword phrases gets your website found. Don't get caught in the rut where website owners want to drive traffic to their website homepage. Your site should have dozens of pages (maybe hundreds) and each one is a destination. That destination should target a specific service (building rock walls, for example) and every page can promote your broader list of services.