Network applications: some jargon Process: program running user agent: interfaces within a host with user above"and 口 within same host,two network" below processes communicate o implements user using interprocess interface communication(defined application-level by Os) proToco o processes running o eb: browser different hosts o E-mail: mail reader communicate with an o streaming audio/video application-layer media player rotoco 2: Application Layer 42: Application Layer 4 Network applications: some jargon Process: program running within a host.  within same host, two processes communicate using interprocess communication (defined by OS).  processes running in different hosts communicate with an application-layer protocol user agent: interfaces with user “above” and network “below”.  implements user interface & application-level protocol  Web: browser  E-mail: mail reader  streaming audio/video: media player