Outlinks can be considered to be the opposite of backlinks. Giving a link from my web site to another website would be considered an outlink for me. For the website that the outlink links to, it is a backlink. Placing too many outlinks would drop the value of your website on search engines.
Outlinks represents the links given to websites. If you are linked to, for you it is a backlink. Having too many backlinks could affect your website's quality according to search engines such as Google. For good rankings it is important to find a good balance between outlinking and being backlinked to.