Your website is like a public transport system (Bus, Train…), it must pick up the visitor from any location and take the visitor to the destination where he is intended to go. Then it is said to have a good conversion rate and well optimized for user navigation.
For instance, a person arrives to your website through Google with the term website design. Then the landing page (say website.com/website-design.html) must satisfy its goal, taking him through website gallery page, from there to templates page, then to enquiry page and make him to fill up the enquiry form. Everything must be inducing him to do this process.
This process can be named as User navigation optimization. This is different from Search engine optimization. Both combined can be called as Website optimization.
If search engine optimization is alone carried out then the website will have more visitors but no one interested with your website. If user navigation optimization is carried out then the website can convert but no one will be there to convert. If both are together carried out then the website will be the most productive in the market.
Only few people in the world know this. How to do website optimization? Leave it to us. We are professionals.