How can any storage device keep information once unplugged from the computer/power?

All of us use memory cards or hard drives to store our data. From pictures to important documents, we save everything in our backup devices. But, how can a small piece of hardware hold such a great amount of data? That too, without any power supply or computer connection.

It is an amazing but quite straightforward mystery that we are about to debunk. To understand the concept behind how our information is kept in a storage device even after it is unplugged from the computer/power, let us take help of a practical example.

All you need is a board, some switches, a marker, some bulbs, and a power line. Once you have all the required equipment, you can perform the following experiment:

  • Step 1

First of all, grab the circuit board and attach four switches to it.

  • Step 2

Now, connect a bulb to each one of the switches.

  • Step 3

Take a marker, and name the bulbs 1 through 4.

  • Step 4

Connect your setup to the power line.

  • Step 5

Now, turn off the switch of bulb number 2.

  • Step 6

You will be left with three bulbson, and one bulboff.

  • Step 7

Turn off the power supply.

You will see that the switches retain their position instead of going back to how they originally were. Now, even if you store this device in a drawer for years, it will remain as it is without going back to its original position.

All the storage devices work on a similar principle. From the ones that you buy from the market to the ones that are used industrially, the basic concept is the same. This is how all the storage devices store data and conserve it for longer durations of time; regardless of how long you keep your device disconnected. Whenever you connect it with the power supply, it will resume from where you left.