how to explain to a child WHAT is BTC made of which is received as reward for mining a block? i looked at different questions in this forum but cannot still clearly figure out. i am not a developer.
ok, we have currently 6,25 bitcoin as reward for miners. how to understand in 1-2 non-technical sentences what do these 6,25 bitcoins (or millions of satoshis) represent? is this just a line of code (just numbers) which was programmed at the beginning?
i understand principle of bitcoin monetary policy, mining main principles, etc... i just do not understand WHAT is this 'coin' exactly... imagine me as child, how would you tell me what do these 6,25 numbers represent itself, what are they made of, are they just numbers we send to each other in transaction? any comparison to any currently mainstream store of values like numbers on banknote, gold ounce, etc...
thanks in advance
The 'coin' is an unspent transaction output (UTXO). It's a long number which specifies a location and some code to allow the UTXO to be accessed by a further transaction which supplies the right key. So ...

it's not a coin really
you never get sent the 'coin'. It remains on the blockchain.
you specified the utxo location before the block was mined, back when you put it in the block you mined. At that time you also created the right key to access the utxo value later.
if you have trouble with the idea that a number can have value, I suggest you consider what value your bank password has.
the value is on the blockchain, visible to all. You have control of it with the right key in your wallet.