There are several endpoints across the API that expect a person id as part of the URL, this is OK if the client knows the person id, but there are some scenarios where it might not be known, for example when using tickets.
For this scenario the API supports the -me- alias which can be substituted in any URL that expects personId.
The http://localhost:8080/alfresco/api/-default-/public/alfresco/versions/1/people/-me- request shows how this can be used to retrieve the profile information of the currently authenticated user.