What is the most important communication standard today for linking disparate computers and networks?

The most important communication standard today for linking disparate computers and networks is the Transmission Control Protocol/Internet Protocol (TCP/IP). This suite of protocols forms the foundation of the internet and enables different types of devices and networks to communicate effectively over vast distances.

TCP/IP is essential because it standardizes how data is transmitted across networks, regardless of the underlying hardware or operating systems. It breaks down data into manageable packets, ensures reliable delivery through acknowledgments and retransmissions (TCP), and routes those packets through various networks until they reach their destination (IP). This capability allows for a seamless flow of information between computers, devices, and systems globally.

While the International Standards Organization (ISO) establishes a variety of international standards, it does not specifically define a protocol for network communication like TCP/IP does. The Open Systems Interconnection (OSI) model is a conceptual framework used to understand and implement network protocols, but it is not a protocol itself used for communication. File Transfer Protocol (FTP) is specific to transferring files and operates over TCP/IP; however, it does not encompass the broader communication needs of linking different systems and networks. Thus, while FTP serves a specific purpose, it is the TCP/IP suite that underpins overall network communication today.