Multiple Sales Pipelines, originally released in beta, is now a fully available feature letting you set unique stages for each distinct sales process your business runs, rather than forcing everything through one shared pipeline.
A layout is the form used to capture a record's details, and a module can have several layouts for different kinds of record. A pipeline is the sequence of stages a Deal moves through, and each pipeline can be tied to a specific layout, so a different sales process automatically gets its own stages depending on which layout a Deal uses.
Selecting a value in a Deal's Pipeline field determines which set of stages appears for that Deal, both on desktop and mobile.