Comment by Gigachad

E-Ink is a specific company’s name which can’t be used to describe the same display technology when used by any other company.

Today e paper is widely understood to mean the display technology which companies like e ink and waveshare use for displays which don’t need power to retain an image.

You’re right that historically it’s been confusing. Historically e ink was the only company making these displays since it was all patented so using their brand name as the technology name worked better back then than it does today.