Glossary ï 189WAGO-I/O-SYSTEM 750ETHERNET TCP/IPGGatewayDevice for connecting two different networks. It converts the differentprotocols.HHardwareElectronic, electrical and mechanic components of a module/subassembly.HeaderA portion of the data packet, containing, among others, the addressinformation of the receiver.Host computer / SubscriberOriginally used to describe a central mainframe computer accessed fromother systems. The services provided by the subscriber can be called up bymeans of local and remote request. Today, this term is also used to refer tosimple computers which provide particular central Services (i.e. UNIX-Subscribers on the Internet).HTMLAbbreviation of hypertext markup languageHTML is the description language for documents on the World Wide Web. Itcontains language elements for the design of hypertext documents.HTTP(Hyper Text Transfer Protocol) client server TCP/IP protocol which is usedon the Internet or Intranets for exchanging HTML documents. It normallyuses port 80.HubA device which allows communication between several network users viatwisted pair cable.Similar to a repeater, but with many outputs, a hub is used to form a startopology.