Types of toolchain - native versus cross toolchain
For our purposes, there are two types of toolchain:
Native: This toolchain runs on the same type of system, sometimes the same actual system, as the programs it generates. This is the usual case for desktops and servers, and it is becoming popular on certain classes of embedded devices. The Raspberry Pi running Debian for ARM, for example, has self-hosted native compilers.
Cross: This toolchain runs on a different type of system than the target, allowing the development to be done on a fast desktop PC and then loaded onto the embedded target for testing.
Almost all embedded Linux development is done using a cross development toolchain, partly because most embedded devices are not well suited to program development since they lack computing power, memory, and storage, but also because it keeps the host and target environments separate. The latter point is especially important when the host and the target are using the same architecture, X86_64...