To create a user or a group in AD, you need to use the Active Directory Users and Computers (ADUC) tool, which you can access from the Start menu or the Administrative Tools folder. You can also use the Active Directory Administrative Center (ADAC) or PowerShell commands for more advanced options. To create a user, right-click the organizational unit (OU) where you want to place the user, and select New > User. Fill in the required fields, such as name, logon name, and password, and click Next. You can also configure other settings, such as account expiration, profile path, and group membership, on the following screens. To create a group, right-click the OU where you want to place the group, and select New > Group. Enter a name and a description for the group, and choose the group scope and type. The group scope determines the visibility and membership of the group in the domain or forest, while the group type determines how the group can be used for security or distribution purposes.