Computer technology is a technology that instead of building a physical machine for each application builds a logical or virtual machine.
The logical machine is general purpose and can be put to any specific problem.
Each specific problem is implemented in the logical machine by software. Software is thus the most important element of computer technology.
Software enables the mass production of cheap mass-produced physical machines that can be turned to any application, rather than building expensive special-purpose hardware.
Not only that, but software is flexible and can be improved with new features over time without the need to replace the original physical machine – only the logical machine is changed and this is cheap to distribute (now over the network, so nothing physical needs to be produced or shipped).
An important fact of computing is that with just a few facilities the complete power of computing can thus be realised. No machine can do ‘magic’ instructions that makes it more powerful than others. Interaction with the physical world is a little different, but all machines with the basic functionality are equivalent at the software level.
The important thing about this is that all machines can be translated into other machines. This is important about producing software – high-level languages which express problem domains can be translated to machine-oriented executable programs. Note again that interactions with the physical world are different – hardware may include an instruction to ‘move robot arm up’, ‘read current image from photo cell’, etc and these may be given by equivalent statements in a high-level language – there is no need for low-level systems languages (although it can be argued that such control makes the language low-level).
However, most software is independent of physical sensors (input devices) and activators (output devices).
Computer technology is about the effective and efficient implementation of these ideas.