I'd say that fundamentally we are manipulating streams or arrays of numbers. Everything is built on top of that. Each character in a tex is a number. Each pixel

I'd say that fundamentally we are manipulating streams or arrays of numbers. Everything is built on top of that. Each character in a tex is a number. Each pixel is a number. Each sample of sound is a number. For computers how the number ends up being transferred to the puny meatbag is completely incidental. In more practical terms at least for me, vast majority of stuff I mangle through shell is not really text but structured data, typically either some sort of tree or a table, or something in-between. Sometimes the structure is more ad-hoc, sometimes it is very rigidly defined, but it's still there