What are the difference between transaction chain in bitcoin and blockchain used in bitcoin?
Is it sufficient to say to each transaction refers to previous transactions in the transaction chain and also each transaction is part of a block which is a part of blockchain?
The blockchain consists of blocks which are collections of transactions. The blockchain is a linked list; each block has 0 or 1 previous blocks and 0 or 1 following blocks.
A transaction chain is a chain of transactions which is completely independent of the blockchain. A transaction chain is a directed acyclic graph; each transaction must have one or more previous transactions and zero or more following transactions.
There is a transaction hash chain. Each new transaction contains a back-link to the hash (often called the transaction ID) of the previous transaction. The blockchain contains blocks, each of which contains one or more transaction IDs. Each block on the blockchain maintains a back-link to the hash of the previous block on the blockchain. So you are correct: There are in fact two chains--a transaction chain and a blockchain.
