The most basic definition of blockchain is a shared, digitized ledger that cannot be changed once a transaction has been recorded and verified. All parties to the transaction, as well as a significant number of 3rd parties maintain a copy of the ledger (i.e. the blockchain), which means it would be practically impossible to amend every copy of the ledger globally to fake a transaction.
Bitcoin’s success has triggered the establishment of nearly 1000 new cryptocurrencies, leading to the delusion that the only application of blockchain technology is for the creation of cryptocurrency.
However, the blockchain technology is capable of a lot more than just cryptocurrency creation and may support such things as transactions that require personal identification, peer review, elections and other types of democratic decision-making and audit trails.
なんとなくオリーブ（塩漬け？）2-3個と一緒に口へ頬張ったら、ん？、口で頬張ったら、あれ、どっちだ？ 口に頬張る？ んんん？