There are other kinds of electronic machines, but basically when someone says computer, they mean digital computer. The machines that we use are called general purpose digital computers. Algorithm then is probably the preferred word by computerniks for procedures. Flow diagrams are simply graphical representations of procedures the computer follows, and if we have a procedure in the form the computer could really do something with directly, then we call it a program. Almost all computers are organized around some basic functional elements which are implemented in hardware. Somehow we have to be able to communicate with the machine, and the machine has to be able to get back to us with results of all its efforts. We call that the input/output equipment, or the I/O equipment. The part of the machine that does the computation is usually called the arithmetic unit. The important technology from the standpoint of microcomputers is disk storage.