Definition of keyboard for English Language Learners. : 1  a row or set of keys that are pushed to play a musical instrument (such as a piano) : 2  a musical instrument that is played by means of a keyboard like that of a piano and that produces sounds electronically. : 3  the set of keys that are used for a computer or typewriter.
Classless Inter-Domain Routing (CIDR, pronunciation: /ËsaÉªdÉr/ or /ËsÉªdÉr/) is a method for allocating IP addresses and IP routing. The Internet Engineering Task Force introduced CIDR in 1993 to replace the previous addressing architecture of classful network design in the Internet.
TRR may refer to: 1  China Bay Airport near Trincomalee, Sri Lanka. 2  Tamper-resistant receptacle, child-safe power receptacle required in new and renovated dwellings since the U.S. 2008 National Electrical Code.3  Target row refresh, a hardware feature of DDR4 used to prevent the row hammer effect from occurring. Tamper-resistant receptacle, child-safe power receptacle required in new and renovated dwellings since the U.S. 2008 National Electrical Code. 2  Target row refresh, a hardware feature of DDR4 used to prevent the row hammer effect from occurring.