What term refers to a standardized set of rules for communication between machines?

The term that refers to a standardized set of rules for communication between machines is "Protocol." In computing and networking, protocols are essential as they define the methods and data formats that devices must follow to effectively communicate with each other.

Protocols ensure that data is transmitted accurately and efficiently across various systems, enabling interoperability between different hardware and software. For instance, the Transmission Control Protocol (TCP) and the Internet Protocol (IP) are critical for managing how data packets are sent and received over the internet.

In contrast, an interface typically describes the point of interaction between different systems or components rather than the rules governing communication. A framework provides a structured foundation for developing applications, including predefined templates and standards, but it doesn’t explicitly define communication rules. A connection refers to the actual link established for communication between systems but doesn't encompass the rules governing that communication. Thus, "Protocol" is the most accurate choice for describing standardized rules for machine communication.