A pathname has six components: a host, a device, a directory, a name, a type, and a version.
19.2.1.1 The Pathname Host Component
19.2.1.2 The Pathname Device Component
19.2.1.3 The Pathname Directory Component
19.2.1.4 The Pathname Name Component
19.2.1.5 The Pathname Type Component
19.2.1.6 The Pathname Version Component