The
computer architecture designed in part by
John von Neumann, and which is used for almost all
modern computers. The
interesting thing about it is that
code is
data — that is,
programs are stored in the same sort of
memory that
variables and other data are.
In the earliest digital computers, such as ENIAC, programs had to be hard-wired with banks of switches or plugs. Accumulators — the forerunner to both memory and registers — could be used to store data only. The von Neumann architecture placed code and data in the same place, accessible via the same bus.
Not all modern computers have the von Neumann nature. For instance, many microcontrollers follow the Harvard architecture.