Maybe the simplest way to put it is that digital means anything that involves some kind of computers and computer language.
Devices involving digital electronics have the advantage of being absolutely precise.
Digital clocks are more accurate than mechanical ones. In modern cars, the digital chips that control the engine are more reliable than the old mechanical systems. Every sound wave is represented by a chain of numbers, which are processed thousands of times a second in order to record and play back the music in real time. An analog tape recorder puts magnetic patterns on recording tape, but in the process it picks up noise from microphones, amplifiers, and the friction of the tape itself. Phonograph records accumulate noise from nicks and dirt in the grooves.