PBN links are links built on a private blog network. PBNs are are group of blogs operated by the same person or company for link building purposes. The blogs usually all have links pointing to a person’s main site that makes money. People will hide the fact that they operate a PBN (aka avoiding footpritns) as Google frowns upon them.
Guest post links are links from posts on other people’s blogs. Individuals write guest posts hoping to get a dofollow backlink at the end of their article. They also hope readers will want to learn more and follow their link to their own website. Publishers usually only accept guest posts when an individual pitches a topic where their content is lacking, and the post is well written.
The main difference between PBN links and guest post links is that Google frowns on PBN links. Actually, they frown on PBNs in general. You should avoid this tactic, unless you 100% know what you’re doing. In order to use PBN links correctly, you need to make sure that they are absolutely “footprint free” and hard to distinguish from real websites. To know what footprints Google uses to identify a network you should refer to a detailed PBN guide in order to know what to avoid.
Guest posting is fine as long as the publisher does not accept money for publishing the post. If you pay to have a guest post published, you’re paying for a link, which is against Google’s policies. The final difference is that guest posts links go on legitimate websites while blogs in a PBN are usually not considered legitimate sites with quality content.
If you are new to SEO we recommend to use guest posts, as they are usually a bit safer compared to PBNs. Only if you 100% know what you’re doing you should use PBN links.