A Private Blog Network (PBN) is a network of websites used to build links to a target website in order to improve its search engine rankings. PBNs are typically made up of expired domains that have been purchased and repurposed with content related to the target website. The links from the PBN websites to the target website are intended to increase the target website's authority and rankings in the search engine results pages (SERPs).
A sitewide backlink is a link that appears on every page of a website. It is usually placed in the footer or header of the website and links to a specific page or website. Sitewide backlinks are a great way to increase the visibility of a website and help it rank higher in search engine results.
A guest post is a blog post written by a guest author that is published on another person's blog or website. Guest posts are often used to increase website traffic, build relationships with other bloggers, and establish credibility and authority in a particular field.
It depends on the website and the type of backlink. Generally, it can take anywhere from 30 minuts.