Application programs need to translate human-readable addresses into the low-level form used by the protocol. The sockets API includes calls to:

• Map host names to IP addresses and back
  
• Map network names to numbers and back
  
• Map service and protocol names to numbers and back
  
• Convert numbers from network-byte order (big-endian) to host-byte order (which is little-endian on OS/2 machines) and back