Technically, your Bitcoins are not stored but they are locked on the public key, when they are successfully locked, each of these transaction data/hash is included in a block by a miner and permanently distributed to every node that is connected to the bitcoin network, these blocks are in sequence and it continues in that manner when a new block is successfully mine and hence the name blockchain.

Bitcoin core and Blockchain.com are two different wallets and none of them stores your bitcoin but store your private keys and helps you spend your bitcoin.