Final answer:
All digital devices fundamentally require a power source and an operating system to function. The power source provides the necessary energy, while the operating system manages hardware resources and allows user interaction.
Step-by-step explanation:
The two essential things that all digital devices need in order to work are a power source and an operating system. Without a power source, a device cannot function as there is no energy to power the electronic components. For instance, digital cameras require batteries, which can be rechargeable batteries, rechargeable battery packs, or regular replaceable batteries to operate.
Furthermore, an operating system is a critical software that enables the user to interact with the computer and run other applications. It manages the computer's hardware resources and provides common services for computer programs. While some other components like a keyboard, mouse, monitor, or printer provide input and output capabilities, they are not fundamental for the operation of a digital device itself.