This TCP flag instructs the sending system to transmit all buffered data immediately.

The PSH (Push) flag in TCP instructs the sending system to:

Immediately deliver data to the application.

Avoid waiting for additional buffered data to form a full segment.

This is important in interactive communications like Telnet or SSH, where the delay in transmission would degrade the user experience.

From CEH v13 Courseware:

Module 3: Scanning Networks → TCP Flags and Packet Structure