What does the version number in IMAP4 signify?

The version number in IMAP4 signifies the generation of the protocol being used. This designation helps differentiate between different iterations and enhancements of the Internet Message Access Protocol (IMAP), allowing users and developers to understand which specific features, capabilities, and compatibility aspects are associated with that version. For instance, IMAP4 is the most widely used version, and it includes various features like improved message handling, folder manipulation, and support for connections over SSL. The version number thus plays a crucial role in identifying the capabilities and standards associated with that particular iteration of the protocol, ensuring interoperability and proper functionality in different email clients and servers.