The stored-program qualifier is important. Although it seems obvious today, the idea that a program that controls the actions of the computer can be stored in the same type of memory that is holding the data that the program was working on was in fact a major leap of understanding for the early computer designers. Computers are built from electronic components that, while complex in their manufacture and their organization into systems, are essentially nothing more than very small, very fast switches. Switching theory, which is the science of studying systems built from switches, is far older than computer science. Telephone systems are an example of a switching network where calls must be routed through a switching network to find the desired receiver.
Railroads are another example of a switching network.
Consider the problem of making sure that two trains will not try to use the same piece of track at the same time but in opposite directions. The railroad system is a system of switches that control where the trains go and which section of track they will use. Both of these examples are related to the early examples of hacker culture, but the railroad example is of particular importance. The subcommittee of the club responsible for the complicated wiring of the switches that controlled where the trains went were hackers waiting to happen. The switching network of the TMRC railroad was essentially a special purpose computer, but one where the programming was done either by changing wires, or by real-time control of the switch settings by the operator.