You're kidding, right?
Almost automatically, the phrase that came to mind was "a decentralized, distributed ledger of transactions." Of course, this would mean absolutely nothing to my son. Then I realized it probably means a whole lot of nothing to many adults, too.
So, how best to describe blockchain in its simplest form? Well, this was bedtime--so I tried my hand at telling him this story.
A Magical Village
Once upon a time, there was a tiny, magical village filled with tiny, magical people. In this village lived a young boy named B.C., and today was his birthday. His parents had bought him a wooden, toy sword, which he was now swinging about in his front yard.
The thing about this sword, and most everything else in the magical village, is that it hadn't always been a sword, nor had it always been in B.C.'s possession. Luckily, in this magical village, there was a way to find out where that toy sword started, and each step it had taken on its way to B.C.'s front yard as his birthday present.
The villagers maintained a magical record at the center of town, which showed all the items that were traded among the villagers, as well as all of the items that were brought in from other villages and sent out to other villages. Everyone could access this record and update it whenever they were involved in an exchange of their own.
So when B.C.'s parents traded for the sword at the local marketplace--for the sum of a bushel of potatoes--both they and the market vendor updated the record to include that exchange. But the record went back much further than this.
You see, before the wooden sword was a sword, it was a wooden board. And before the board was a board, it was rough, unstructured lumber stock. And before that lumber stock lay in a yard waiting to be transformed, it was part of a tall and proud tree in the forest to the south of the village.
Any villager, B.C. included, could discover this information by looking at the magical record. Indeed, it traced B.C.'s toy sword from its days as a tree along each stop on its way to becoming the toy sword B.C. now swung about in his front yard. The same was true for each and every product moving in and out of B.C.'s village.
And what a useful tool this was! It meant that nobody except for all of the villagers together had to keep track of these things. There were no middlemen, as there used to be in the days before the magical record, who charged the villagers to keep track of the comings and goings of their goods.
The community used the record to keep itself informed of the operations of the entire local economy, as did the other surrounding villages. Then, together, they merged these records into one larger record, establishing a start-to-finish list of all of the products exchanged within the kingdom.
B.C. played happily with his sword, never once thinking about where it had come from or how it had been created. But if he had wanted to obtain that information, all he had to do was consult the magical record and it was all right there at his fingertips.
When I'd finished telling him the story, he seemed confused. "But what's a blockchain, Dad?" he asked, as if I hadn't answered that question. So I asked him how the magical record worked in the village. He replied that everyone was a part of keeping it up to date.
I asked him where the magical record was located, and he replied "everywhere." And finally, I asked him what the magical record did, and he told me, "It kept track of where things came from, and who gave them to whom." Pretty good for a 6-year-old, huh?
The bottom line is that the basic explanation of a blockchain ledger includes the following concepts:
It's maintained by every user on the blockchain.
It's decentralized, meaning every user has a complete copy.
It can track the entire transaction history of any given item or currency.
And that's how I was able to keep my 6-year-old's attention and (kind of) explain what "Daddy does." Try doing the same for your children--or even yourself--and the concept of blockchain will be far easier to digest.