packet
termnetworking
A unit of data with its own header, forwarded independently of whatever came before or after it.
The word is Donald Davies's, coined in the mid-1960s for an idea Paul Baran had reached separately, and the naming mattered: it gave engineers, funders and standards bodies a way to discuss the thing without arguing about what to call it. The independence is the whole design. Because each packet carries its own addressing, no device has to remember a conversation, which is what lets a failed link be routed around and what makes the network cheap to scale - and it is also why order, reliability and pacing had to be rebuilt at the endpoints.
Also known as: datagram, frame