Anchor Text Definition
Anchor text is the clickable text in a hyperlink. SEO best practices dictate that anchor text be relevant to the page you're linking to, rather than generic text. The blue, underlined anchor text is the most common as it is the web standard, although it is possible to change the color and underlining through html code. The keywords in anchor text are one of the many signals search engines use to determine the topic of a web page.
Bad anchor text example: Click here!
The anchor text is also known as the link label or link title. The words contained in the anchor text help determine the ranking that the page will receive by search engines such as Google or Yahoo and Bing. Links without anchor text commonly happen on the web and are called naked URLs, or URL anchor texts. Different browsers will display anchor text differently, and proper use of anchor text can help the page linked to rank for those keywords in search engines.
Exact Match Anchor Text
An exact match anchor text has the same keywords highlighted as the targeted keyword of a web page.
Anchor Text Variation
When websites aggressively build exact match anchor text links, a Google spam filter is triggered. It is unnatural for web pages that link to your website to all have exact match anchor text. A bit of anchor text variation is natural, just like how a great portion of the internet's links are naked URLs.
Anchor Text Manipulation
As a result of being a search engine signal for relevancy, it is possible to over-optimize your links' anchor text.
Targeted Anchor Text
Linkbuilders, or SEOs specialized in building links to a website, often control the anchor text from the links they build from other websites. These anchor texts are targeted - the keywords in the anchor text will match the targeted keyword of the page an SEO is trying to rank on.
Backlink Anchor Text
A backlink is a link from another website. The backlink anchor text is the anchor text used by other websites linking to your website. The anchor text of these backlinks help search engines determine the most relevant keywords a web page should rank for.
One-Way Achor Text Backlinks
If website A links to website B with an anchor text backlink and website B does not link back to website A, then you have an one-way anchor text backlink. One-way anchor text backlinks are sought out by SEOs because PageRank juice flows one one domain to another. It is believed that the more one-way anchor text backlinks a web page has from websites with high PageRank, the better they will rank on search engines.
Excessive Anchor Text
Just like keyword stuffing, you can have too much anchor text on a given page. When there are too many keywords on a page linking to too many other pages of a website, or all to the same page but with different anchor texts, you have a case of excessive anchor text. The excessive use of anchor text within your website can lead to Google penalties as it is considered a spammy, user-unfriendly practice.
Anchor Text Distribution
Because link builders are actively building links to their website with targeted anchor text, particular keywords will have a higher share of a page's overall anchor text distribution.
Spammy Anchor Text
A spammy anchor text is a link with an anchor text that has no relationship to the page it exists on or the page it is linking to. Spammy anchor texts are a common black hat SEO tactics to either temporarily rank for competitive keywords such as "pay day loans" or "buy viagra" but can also be used as a tool to harm a competitor's website or individual through negative SEO and Google bombing.
Natural Anchor Text vs Unnatural Anchor Text
When web surfers link to your website, it is inevitable that you will get bad anchor text that does not help identify your web page's topic. However, just like naked URLs, these are natural occurances, and are not frowned upon by search engines. On the flip side, the lack of naked URLs, the excessive use of anchor text, and or a high number of targeted one-way anchor text backlinks are all signs of unnatural anchor text distribution. Search engines like Google may penalize websites that focus on manipulating anchor text when user experience is compromised.
To obtain natural anchor text links to your website, create good content and the links and anchor text should come naturally.