Someone recently asked me in an interview to explain what blockchain is. But, not a technical explanation. Rather, explain it to someone who knows very little about technology. It caught me off-guard, but here’s what I came up with.
For Programmers
“Do you know anything about programming?” I asked.
“Yes, I took an intro course in college.” she replied.
“Great. Do you know what a linked list is?” I asked.
“Yes.”
Wiping the sweat off my forehead, I said “Great. So, blockchain is basically a linked list, but there are multiple copies of it, and it uses cryptography to keep everything secure.”
“Ok, I sort of get it. But can you explain it to someone who doesn’t know what a linked list is?” she asked.
For Beginners
I scratched my head for a minute, and then came up with the following.
Imagine an elephant, like this one:
The elephant has a suitcase on his back containing his things. (I know, you are gonna ask why he didn’t put them in his trunk!)
Now imagine a few elephants, like these:
Each elephant has its own suitcase and is holding the tail of the one in front of them.
Using this analogy, each elephant is a block in the blockchain with a suitcase containing some information. Each block only knows what the previous block is (i.e., holding the tail).
That’s a basic blockchain. But, we need to add two additional aspects.
First, blockchain is distributed. This means that the blockchain is copied to multiple participants (called nodes). Using our elephant example, the exact chain of elephants is copied to multiple participants, like so:
Second, blockchain uses cryptography to keep everything secure. This means that when information is exchanged in the blockchain, it uses private and public keys and more to keep it safe. Trust us.
There you have it – blockchain is just a bunch of elephants in a line.
Does it make sense? Can you explain it more simply?
As a side note, I actually explained it in my interview as camels in a line holding their tails, but then it was pointed out that camels don’t do that.
Phlogtastic 