Building back-links is at the heart of off-page SEO. Search engines use back links as indications of the linked-to content’s quality, so a site with many high value back links will usually rank better than an otherwise equal site with fewer back links.
There are three main types of links, defined by how they were earned: natural links, manually built links, or self-created links.
Natural links are editorially given without any action on the part of a page owner. For example, a food blogger adding a link to a post that points toward their favorite produce farms is a natural link.
Manually built links are acquired through deliberate link-building activities. This includes things like getting customers to link to your website or asking influences to share your content.
Self-created links are created by practices such as adding a back link in an online directory, forum, blog comment signature, or a press release with optimized anchor text. Some self-created link building tactics tend toward black hat SEO and are frowned upon by search engines, so tread lightly here.