What is a Site linking?
First is providing more information about that particular Term or Keyword.
Secondly it is done for Keeping Visitors Busy with more Informative Topics or Articles related to the same content and thus, increases the page views.
These methods of increasing page views increases the Page Rank also, as higher the number of visits – higher the value in Analytics which makes the Post or Article Popular and thus, brings the blog to a Good Rank.
The method of using links with multipurpose/ uses is here Termed as Site Linking. now, Site Linking can be further categorized in to two ways:
1) Internal Site Linking
2) External Site Linking
What is an Internal Site Linking?
This Category consists links that are connected within the Same Site Hosted. i.e. all the Links are inter-connected on the Same Website or URL.
eg. A link on page http://reliable4you.com/jyoti-amge-worlds-smallest-woman-from-india-guinness-world-record-winner/ has a link to a page http://reliable4you.com/chandra-dangi-worlds-smallest-man-guinness-world-record/.
How: In the above example, you can see the highlighted terms for you in both the page links which are a part of Same URL or Website only.
Usage: This kind of links lets the user get engaged between the content to get Specified Knowledge as well as increase the Page Results. not, only this Ends here, you can also track people to your OLD yet Powerful posts which have Shared a Great Knowledge but, is dragged some where (nearly unreachable) for the new blog followers who have missed that.
Note: Due to new posts come over the older posts on Categories and Archives, new visitors leave or miss OLD yet powerful Posts. this Internal Site Linking can help in connecting visitors with those Articles or Posts, by linking to them with relevant keywords.
What is an External Site Linking?
This Category consists Links which are Connected or Linked to the Pages or Sites which are Hosted on Different URL’s. This Includes Sub-Domains or Other Sites Owned by Same Person or Sites totally out Linked (Sources or Sponsors).
Note: Sub-Directories (In Some Cases are Excluded) are counted as Internal Site Links only.
See: Difference Between Sub-Domain or Sub-Directories
eg. A Link on This Page is Linked to http://himanshug.com/ which is an External Site Link either used for Author Details or for examples.
How: In the above example, you can see that the highlighted term doesn’t have its address starting from the the current sites address i.e. Reliable4you.com, and thus, will take to a new Website or Webpage for more details related to that link.
Usage: This kind of Linking is used to gives Credit links, Back-links, Sources, Promotions, Advertisements etc. No matter what is the reason behind using External Links by a Webmaster in his Site or Pages, but, the thing is very clear that it do benefits either to Webmaster or Clients but it always benefits to a Readers as they tracks new places on the Web (full of Knowledge), as every site or page do contain some information which gives knowledge in either way.
Note: Creating too much External Links or too Pages or Sites Disliked by Search Engines will Leave a Negative Impact on your Page Rank. If, you Really need to place a link for External Sources about which you are not updated too much than you must use a No-follow tag between the Links.
How to do Site Linking without Effecting SEO & Page Rank?
As, just above this you can see a para about External Pages/Sites Disliked by Search Engines. That above para had a complete article over it (must Read More>>) where you can see ways to handle these issues which has regular impacts on doing SEO and saving Page Rank.
If you are UN-intentionally promoting or promoted a blocked site, you want be spared as all these linking activities are tested by robots file which is really a Robot working on commands given. They further pings and tracks your links and their destination until or unless you have requested them for not following a specific Link.