A heatmap is a graphical representation of data that uses a system of color-coding to represent different values. They show where users have clicked on a page.| Optimizely
A conversion occurs when a user completes some predetermined action on your site. Typically tracked in marketing analytics tools.| Optimizely
Search engine optimization (SEO) is the art and science of getting pages to rank higher in search engines such as Google.| Optimizely
The conversion rate is the number of conversions divided by the total number of visitors.| Optimizely