Can a transaction disappear? (Orphan Blocks) Can a transaction disappear after transfers transactions to Bitcoin networks.

I heard about the Orphan Block.
Are all transactions in the Orphan block going away?

Is there a possibility that transactions will be lost in bitcoin network?
When a block, or set of blocks, is dropped (orphan block, minor fork, chain reorganization), any transactions in those blocks are returned to the mempool. Usually, many of these transactions will be contained in the blocks that replace the dropped blocks, and end up in the chain anyways.

It is relatively rare for a transaction to outright disappear, and will never happen for a transaction with sufficient confirmations. It is not unheard of for transactions with very low fees to be evicted from the mempools of enough nodes to be lost entirely during times of network congestion, however.