are sometimes called "intelligent networks" or "content-based routing networks" and they are generally network technology that can use the content of a network packet or message to take some sort of action. During the rise of the internet many routing decisions were made at layer 4 i.e. based on the TCP/IP address and/or the port number.
Application-oriented networks work at layer 7 of the OSI stack and because they can examine the content of the message they can make routing decisions based on many different criteria including such things as the value of the purchase order or the ship date.
Most Application-Orientated Networks manipulate structured data based in a human-readable format like XML.