In print and writing, braille is raised dots on paper, placed their by a machine or by a person using a slate and stylus. Translating that to machines has meant, for the most part, creating special braille readers that use a pin in place of each dot, which is raised or depressed to match the word it's displaying. Think of pixels on a monochrome computer monitor, only a lot more cumbersome to create. There are braille devices that can turn text on a screen into readable braille, but they're expensive and usually only show a single line of text at a time. That's great for a 4-digit tool like this South Korean watch that displays in braille, but not so great if someone wants to read a book or even just an article.