What are backlinks (external links) and how do they affect SEO?

Backlinks (external links) are links located on other websites that point to yours. In SEO, they are considered a key ranking factor because they reflect the authority, popularity, and trustworthiness of a resource from other sources online.

How backlinks work

When one website links to another, search engines interpret this as a recommendation signal. The more high-quality and topically relevant links a website has, the more likely it is that a search engine will find it useful and deserving of higher rankings.

Main types of backlinks

• Natural links - appear organically when other sites link to useful content.
• Manual links are placed as part of an SEO strategy (guest articles, partnerships, directories).
• Self-created links – placed by the user (forums, comments, profiles), often have less weight.

Backlink quality

Not all links are created equal. Search engines evaluate not only the quantity but also the quality of links.

• Donor site authority - links from trusted and popular resources carry more weight.
• Thematic relevance - links from sites with similar topics are valued higher.
• Anchor text - The link text helps people understand what the landing page is about.
• Naturalness of the link profile - a sharp increase in links can be perceived as manipulation.

Impact on SEO

Backlinks affect SEO in the following ways:

• increase domain authority;
• improve positions in search results;
• speed up indexing of new pages;
• increase search engines' trust in the site.

Risks of low-quality links

Using spammy or irrelevant links can lead to lower rankings or filtering by search engines. Therefore, it's important to build a natural and high-quality link profile.

Result

Backlinks are an important SEO factor because they reflect an external assessment of a website's quality. The higher the quality and naturalness of the links, the greater their positive impact on search rankings.