Link juice is a term in SEO that means to power of any link passed to the site. These links may be from external or internal sources. The amount of links help search engines find and index your content. The quality of link juice is more important than the quantity.
Map tree is nothing but a graphical information about how your website is connected (interlinked) to one another. For example, if you have a big eCommerce website with too many links and categories and sub-categories, you need a visual structure for you, users and search engines understand the linking structure of your website. This will result you to understand the site structure and the better site structure means better results in search engines.