Final answer:
The unit of data routed between an origin and destination on packet-switched networks like the internet is called a packet.
Step-by-step explanation:
The unit of data that is routed between an origin and a destination on the internet or any other packet-switched network is called a packet. This foundational concept in networking is critical as packets are the basic units of data that are encapsulated for transmission over networks, including the vast network of networks we know as the internet. Each packet contains not only the user's data but also important metadata which includes information like the source and destination IP addresses, sequencing information and error detection codes, ensuring that the data can be reassembled correctly and verified for integrity at its destination.