Main Site > Buffer Site > Tier 1 > Tier 2 > Tier 3
Buffer sites are made directly to the main site. The backlinks are created to the Buffer site accordingly. High quality backlinks are users and Tier 1 and low quality backlinks are follows by Lower Tier backlinks.
There are varying opinions on exactly that hierarchy, minor change to what you said but significant enough to mention for example
"buffer sites" ( smaller sites that are separate from your money site that link to your money site and are on a very different host and IP) have complete control over the content of, usually web 2.0 with a really high DA and PA are actually just a component of a good Tier 1 strategy, with the reasoning for having them as buffer sites being that you intend to blast the shit out of them with GSA/Scrapebox/money robot etc crap links that extends several tiers out to boost its ranking and Authority, knowing that these buffer sites are hosted on Web 2.0 is that heavy strong enough profile to handle such a blast
If anything negative happens as a result of those spammy backlinks, you can simply remove the link from your buffer site that you control at your leisure without having to involve asking anybody else to remove it and either avoid or reverse any negative impact has potentially toxic links could have. These are also known as pillow sites, parasite sites Barnacle sites Etc.
Tier one would Encompass not only the buffer sites mentioned above, but also any high quality guest posts that link directly to your site, any editorial mentions of your sight in any Resource page or within the context of an article, or that in general in any way linked directly from their website to your website are considered part of Tier 1, because there is no whole integer between 0 and 1.
Tier 2, is any link from anywhere of any kind of any quality level that links to the specific pages on which your Tier 1 links exist.
Obviously, if you have a back link from Wikipedia to your site that doesn't mean that everybody that links to Wikipedia is part of your tier 2.. However, let's say your site was cited as a source on a Wikipedia page that don't specifically with mountain lions, any site that links to that page could technically be considered part of your tier 2.
That being said for the sake of sticking to things that are largely within our control, Tier 2 of your link-building strategy will be any Pages or links that you build from anywhere on the web of any kind, whether they be forum, blog comment, Wiki citation, exploit links profile links Etc that point to that specific page on mountain lions, (that specific page on Wikipedia that cites your website as a citation and links to your site) is considered part of your tier 2.
You can build as many tears as you like carrying on the same exact stated method and definition as above ad infinitum and ad nauseam, but last i read on the subject though he must there is evidence that they may look back is up to possibly six or seven 6 or 7 tiers In some cases so doing that might be considered gross Overkill and it also might be considered getting a jump on the competition depending on how you look at it and how long you plan to stay with the recipient of said backlinks