When web sites link to each other, either directly or indirectly through a number of different pages, a search engine might consider those links to be reciprocal links. A reciprocal link is an agreement between two webmasters to provide a hyperlink within their own website to each other's web site. Generally this is done to provide readers with quick access to related sites, or to show a partnership between two sites. Reciprocal links can also help to increase traffic to your web site in two ways.

It is typically an exchange of links(You scrub my back and I will scrub yours!), that may sometimes backfire if not done naturally.

In essence, a reciprocal link is a quid pro quo, or a “you scratch my back, I'll scratch yours” situation.

Reciprocal link
 

A link exchange occurs when an agreement is made between two brands to trade links to boost SEO and site authority by essentially saying, 'you link to me, and I'll link to you." In essence, a reciprocal link is a quid pro quo, or a "you scratch my back, I'll scratch yours" situation.