Posting of a website or blog owner on other websites or blogs is called guest blogging. It is also called guest posting. The main purpose of guest blogging is to create backlinks. Creating backlinks improves the Google ranking of the blog website.
In guest blogging, an article is written according to the category or niche of another blog and in return the person who posts it gets a backlink. This backlink is usually given in the author box at the bottom of the written article.
This is a great link building strategy that comes under white hat seo.
When you write a guest post on a high quality blog, it is very good from the point of view of SEO. Backlink from High Quality Blog increases the Pagerank of your site in Search Engines.