Transactions are bundled into a Block. Blocks are then chained together into a "blockchain".
The way the chain of transactions and linked blocks are verified is what we call consensus algorithms. The consensus algorithm varies based on the incentives for the network operators/participants: Proof of Work, Proof of Stake etc.
Not every transaction has a recipient; in this case, this is a smart contract, which is basically a script deployed on the blockchain. In most cases, every blockchain transaction is a script but the execution/decryption of this script is tied to someone (recipient's) secret key. So for smart contracts, usually there is no recipient.
If you're not familiar with blockchains, I would advise that you don't dig into the technical implementation as it's quite complicated. Think of the datasets as regular databases tables connected by primary keys (in this case, fields). Focus on high-level constructs as below: