How can a computer keep memory when it runs out of battery?

Question

This very well might be a stupid question, but from my understanding a computer saves his memory using binary bits, so if electricity runs through the bit it is 1 and if there’s no electricity it is 0, my question is if that is how information is stored how does my computer remember things even if I would unplug him for years?

Answer 1

That's because you're thinking of it in a too naive way. While running, the states 0 and 1 might be represented using electricity only, but that won't prevent you from using physical or chemical media in different ways to do so as well.

• When using a traditional HDDs and tapes, the states are saved by magnetizing or demagnetizing parts of a disk or tape.
• SSDs (oversimplified) on their own are capable of storing tiny charges to keep values.
• CDs, DVDs, and Blu-ray discs represent values by different heights/reflection properties.
• Punch cards used clearly visible holes to represent binary differences.
• Limited information, such as the current time and date is typically saved and updated using a small battery, which may least for days, weeks, or even years.