Computers represent data using binary numbers systems of 0s and 1s. Data is processed by the central processing unit and memory of a computer. Common computer memory types include volatile RAM and nonvolatile ROM. External devices connect via ports like USB and data is transferred using standards like text encoding. The internet allows sharing of data through email, file transfers, online storage and chat services. Operating systems manage hardware, run programs, and provide utilities while differentiating between single-user and multi-user models. Storage devices save data magnetically or optically when the computer is off in formats like hard drives, disks, tapes and optical discs.