IPX, IP, and Appletalk
Are standard protocols that describe how computers transmit data and recognize devices. When protocols are followed, computers using different operating systems and software from different vendors can work in the same internetworking environments.
For example, sharing information in a network with UNIX workstations, PCs, and Macs would be impossible if each vendor invented their own methods for connecting, sending, and receiving data. Instead, IP, IPX, and Appletalk, as different as they are, all arrange information in data packets in a way that can be interpreted by each other so that they can coexist in a single network.
The Open Systems Interconnection (OSI) model is a standard that was created by the International Organization for Standardization (ISO). It defines a layered reference model for an environment in which a process running in one computer can communicate with a similar process in another computer if they implement the same OSI layer communication protocols (illustrated above).
Protocols are defined by a standards organizations. Standards cover how computer equipment and data transmission operates. Standards are actually recommendations that enable multiple vendors to supply the demand for internetworking hardware and software.