Author Profiles are used to ensure that your name and your work are tied together. With the sheer multitude of authors on the internet all sharing and proliferating their work, people with similar or the same names will often mistakenly be attributed to a work that is not theirs. To make sure this does not happen, it is prudent to set up author profiles for as many databases as possible. Thankfully some, like ORCID, will try to do this for you, but in some cases it is necessary to set up a site-specific profile and then link all of your work to your name.
