Visitor management is one aspect of Access Control. It might include photo documentation through the use of security cameras of both the parking lot and entry points, it might include nothing more than an intercom and security controlled electronic door lock.
Before choosing the security tactics you use for Visitor Management, determine the goal. There’s so much gear out there that it’s easy to go overboard and beyond your needs. Better to be streamlined and efficient than burdened by too much tech.
See the link for ACCESS CONTROL.