A pinhole is a configuration setting in the firewall that allows access to specific services running on a campus computer. For example, for users on the Internet to access a campus web page, a pinhole must be configured on the firewall to allow requests to the web services on the computer hosting the web site. This service description is usually called a port. Web services commonly use Port:80.
If a particular computer - we'll call it DeptWebServer1 - needs to display a departmental web page on the Internet, the departmental IT Coordinator would request that a pinhole be configured on the firewall to allow DeptWebServer1 to be accessed via port 80. This allows anyone to access the department web page over the Internet but not to access other services on the HSU network. By limiting access to just the services needed to meet a web user's requirements, the risk of attacks from the Internet reaching vulnerable computers on the HSU network is greatly reduced.