Logins are used to access Microsoft SQL server and to create database users. You should create as many logins as many users you will have.
To create an Microsoft SQL login:
Note: you can change password by clicking the Change icon against the login name in the Controls section.
To delete login, click the Trash icon against the login name, in the Controls section.
Important: With deleting a login, Parallels H-Sphere will delete all databases created under it and also all users under the databases. Also if you have some users under this login that are associated with another database, these users will be deleted as well. Please make sure you want to delete the login before clicking Trash.