An unconfirmed transaction is that transaction that has not been included in a block, and not completed also. Every transaction requires at least one confirmation to complete the transaction.

The common reasons for unconfirmed transactions are:

You have made the transfer. The Bitcoin network needs at least 10 minutes to include the transaction in a block.
The blockchain fee is very low. Thus, the lower the transaction fee, the lower your transaction’s priority in the Bitcoin network. Therefore, it takes longer confirmation to be a valid transaction.

An unconfirmed transaction in the context of Bitcoin refers to a transaction that has been broadcast to the network but has not yet been included in a block on the blockchain. When someone initiates a Bitcoin transaction, it gets broadcast to the decentralized network of nodes. Miners then pick up these transactions and include them in a block. The block is subsequently added to the blockchain through a process known as mining.

Until a transaction is included in a block and added to the blockchain, it remains unconfirmed. During this time, the transaction is visible on the network, but its status is not considered final. Unconfirmed transactions are susceptible to certain risks, such as the possibility of being double-spent.

Once a miner successfully includes the transaction in a block and that block is added to the blockchain, the transaction is confirmed, and its status becomes more secure. The number of confirmations increases as more blocks are added to the blockchain, providing a higher level of certainty and security for the transaction.

In summary, an unconfirmed transaction in the Bitcoin network is one that has been broadcast but has not yet been included in a block on the blockchain, and its status is not yet considered final.