The GCC compiler uses 'triples' when referring to the host system that the compiler runs on or the target system that a compiler will generate binaries to run on.
The term 'triple' refers to the method used in the GNU/Linux operating system to designate a specific host or target. It is separated into the following components:
The <operatingsystem> may be further divided into an optional operating system and ABI portions. For example the Linux OS and the GNU hardfloat ABI might have the following <operatingsystem>, "-linux-gnueabihf". Whereas a bare-metal target will not have an OS but only the embedded ABI, "-eabi".