If you have a blog which is updated by multiple authors, there is every likelihood that you might need to post or update a post for another user. What if you have outsourced your writing and the writers email you the posts and you then post these on your WordPress site. It is also possible that one of your users can not access WordPress site with his user name and password and you need to post under his or her username.
It is possible that you can post on your WordPress under a different username that you are logged into. But don’t panic. This can be only done by a user who has elevated privileges on the WordPress website for example an administrator.
In order to switch user and post under a different username on the WordPress site, you need to go the bottom of the New Post page and select the author from the Author box drop down menu. Select the author, and click on publish and the post will be published under the name of the user that you selected and not under the name of the admin user.
If the Author box is not visible, you may enable it from the screen options on the upper right side of the page.