lots of good answers already. my tldr: it's a terminal-agnostic tool to split a window vertically or horizontally so you have multiple shell sessions on the sa

lots of good answers already. my tldr: it's a terminal-agnostic tool to split a window vertically or horizontally so you have multiple shell sessions on the same screen (and can move between them). Lots of other great reasons too but that's the major one IMHO.