What enabled computer-to-computer transfer of data between companies, usually over private telecommunications networks?

The correct answer is Electronic Data Interchange (EDI) because it specifically refers to the structured transmission of data between organizations electronically, which allows for seamless and automated exchanges of business documents such as purchase orders, invoices, and other critical transactions. EDI standardizes this process, enabling companies to communicate efficiently without the need for paper-based documentation, thus significantly speeding up the transfer of information and reducing errors that could occur in manual data entry.

This method typically takes place over private telecommunications networks, which enhances security and reliability for businesses exchanging sensitive information.

While network protocols are essential for defining rules and conventions for communication between networked devices, they do not specifically facilitate the data transfer between companies in the way EDI does. Similarly, File Transfer Protocol (FTP) is a standard network protocol used for transferring files over a TCP/IP network but does not inherently manage the structured exchange of business documents between companies like EDI. Data synchronization, on the other hand, involves ensuring consistency between systems and may relate to internal data management rather than the direct inter-company data exchanges that EDI supports.