Q: Are links within our own page (to other pages on the site) counted as “link juice”? If two blog posts, Part I and Part II are written and on posting Part II, it is linked back to Part I, is this considered as link juice?
A: Link juice flows between two web pages or websites. If that one “object” on the web is linked to another “object”, link juice flows. Google considers link juice as it helps in building up the PageRank of the “object”. The objects with higher PageRank will than rank higher on relevant Google searches.
If we get into how all this is practiced, it is the External links to your site (blogs, Tweets, pages, and websites) that count for SEO. If an external website has an A HREF link from the site to your site, the link juice will be counted as a Vote and help your website score a top 10 rank on Google. So, getting links really helps.
The question asked addresses to more special case of link juice known as “link sculpting”. When the home page links from self to your landing page, the “link juice” flows from home page to the landing pages and helps those pages do well in Google search. Many SEO experts also sculpt the links on the website around targeted keywords and phrases, especially how home pages links to the landing page and linking of the site navigation. So, you should pay attention to sculpting links from homepage and in-site navigation to the other pages on the website. Having enough inbound link energy can make a big difference.