(1) See
terms of service.
(2) (
Type
Of
Service) A field in an IP packet (IP datagram) that is used for quality of service (QoS). The TOS field is 8 bits, broken into five subfields.
(3) (
Tape
Operating
System) An OS for IBM's System/360 Model 30 in the mid-1960s. It was superseded by DOS/360.