The sequential nature of computers: an instruction is analyzed, data are processed, the next instruction is analyzed, and so on. Hungarian-born John von Neumann (1903-1957), an internationally renowned mathematician, promoted the stored program concept in the 1940s.
John Luis von Neumann
Von Neumann's name is perhaps mentioned more than any other early computer pioneer because the subject of sequential operations versus parallel operations is often discussed. (Image courtesy of The Computer History Museum, www.computerhistory.org)