What is the difference between udp and ip from fuctional point of view?

Udp is a protocol of transport layer and ip is the protocol of network layer. Network layer is third level layer and transport layer is fourth level layer in osi reference model. Every upper level do the task given by its lower level. Ip set rules for the address of the source and destination node in the network. Where udp set the rules transferring of datagram from source to destination over network. For more details go throgh the book data communication and networking by foruzan.