Characteristics of a computer are generally things we already know. These are speed, reliability, memory, and accuracy, just to mention a few. These characteristics are centered around one key factor and that is data.
Data plays a vital role in the function of the computer system as the system needs data to work, the entre definition of a system is centered on data.
It takes in data, it works or analyses, processes it and returns a feedback. It is only when the system takes in data and processes, we can measure if it is fast (speed), and we can measure its efficiency after giving output. And this is same for all other characteristics.