What is a commonly used network protocol that can be used to connect many different kinds of computers or devices a star?

The most commonly used network protocol is internet Protocol (IP), this is the protocol used within the Internet, this protocol is a derivative of TCP/IP Transmission Control Protocol/Internet Protocol. This is used in 99% of common corporate networks, the TCP components deals with efficiencies of network transmission. TCP/IP or IP overlays the common Ethernet networking topology.