What are private blog networks?

Related questions

1. What is an empty anchor?
2. What is PBN?
3. What are search engine backlinks?
4. How do you create an anchor in HTML?
5. What is SERP in SEO?
6. Do Google reviews affect SEO?
7. What is anchor text in SEO?
8. How do I get PBN backlinks?
9. What is crawling in digital marketing?
10. What is crawling in Google?

Tags

1. #hosted
2. #consisting
3. #individual
4. #domains
5. #wordpress
6. #livejournal
7. #another
8. #possible
9. #blogs
10. #tumbr
11. #typically
12. #private
13. #power
14. #network