Inbound and out­bound links, as well as inter­nal links, are com­mon SEO terms which peo­ple tend to con­fuse. Here is a thor­ough expla­na­tion of the dif­fer­ence between inter­nal, inbound and out­bound links, and the best SEO prac­tices how and when to use which type of links.

Internal links

Inter­nal links are links which point to anoth­er con­tent with­in the same domain. This means the domain of a page with an inter­nal link and tar­get domain are the same.

There are two types of inter­nal links:

• reg­u­lar inter­nal links — point­ing from one page to anoth­er page with­in the same domain
• anchor links — point­ing to a spe­cif­ic place on the same page

The pur­pose of inter­nal link­ing is to offer your vis­i­tors more con­tent they might be inter­est­ed in and keep them on your web­site longer. From the SEO per­spec­tive, inter­nal links help in estab­lish­ing web­site archi­tec­ture and spread rank­ing pow­er through­out the website.

When cre­at­ing inter­nal links it is rec­om­mend­ed to keep the link path rel­a­tive and to use an anchor text.

An exam­ple of a link with rel­a­tive path and anchor text:

<a href="/blog/sample-image.jpg">Sample image</a>

An exam­ple of a link with absolute path with­out anchor text:

<a href="http://www.mywebsite.com/blog/sample-image.jpg"></a>

Keep­ing links’ path rel­a­tive ben­e­fits you in 2 ways:

• domain name change — for exam­ple, if you switch from HTTP to HTTPS, using rel­a­tive instead of absolute paths, will save you going through and chang­ing all inter­nal links on your website
• per­for­mance and speed — when a vis­i­tor clicks on a link with a rel­a­tive path, your site will be able to respond and serve the tar­get page much faster

SEO advice: Use inter­nal links pri­mar­i­ly for read­ers, not for search engines; link to the rel­e­vant con­tent which pro­vides val­ue to the reader.

The difference between inbound and outbound links

Inbound links

Inbound links are all URLs which lead to your web­site and are placed on exter­nal sources. In oth­er words, those are links point­ing to your web­site from oth­er web­sites, social media pages, forums etc.

Inbound links, or com­mon­ly referred as back­links, are one of the most impor­tant SEO fac­tors. Web­sites that rank high in SERP have hun­dreds and thou­sands of back­links. How­ev­er, many back­links can help your rat­ings only if most links come from trust­wor­thy and rel­e­vant pages. Irrel­e­vant and spam­my links can hurt your SEO and even dein­dex your website.

SEO advice: When it comes to link build­ing bear “qual­i­ty over quan­ti­ty” in mind. Use the best tech­niques to increase the num­ber of back­links.

Outbound links

Unlike inbound links, out­bound links send vis­i­tors away from your web­site.

Out­bound links, or some­times called exter­nal links,  are all links on your web­site point­ing to oth­er websites.

Out­bound links have pos­i­tive effects on SEO but only if you tend to link to high author­i­ty pages with rel­e­vant con­tent. Where­as out­bound links pass some of your SEO juice to the tar­get page, you should use them sparingly.

SEO advice: Use out­bound links 1–3 times per arti­cle, and only if the tar­get source con­tent is rel­e­vant and use­ful to the readers.

Dofollow and Nofollow links

Dofol­low and nofol­low are HTML link attrib­ut­es whose pur­pose is to tell search engines if they should or should­n’t fol­low the link, and in SEO terms, to trans­fer or not some of your SEO link juice.

By default, all links are dofol­low. If you want to make a link nofol­low, you have to do it manually.

Google asks all paid links to have the nofol­low attribute, and usu­al­ly, by default, links in com­ments, on forums and all user-sub­mit­ted links, e.g. on Wikipedia, are nofollow.

SEO advice: Use dofol­low links if you link to a trust­wor­thy web­site with qual­i­ty, rel­e­vant con­tent. Use nofol­low links when­ev­er you link to a spam­my web­site for any reason.