Update concepts-transactions.md (apache#11540)

site2/docs/concepts-transactions.md

@@ -21,9 +21,9 @@ All the transaction metadata is persisted in the transaction log. The transactio
 The transaction ID (TxnID) identifies a unique transaction in Pulsar. The transaction ID is 128-bit. The highest 16 bits are reserved for the ID of the transaction coordinator, and the remaining bits are used for monotonically increasing numbers in each transaction coordinator. It is easy to locate the transaction crash with the TxnID.
 
 ## Transaction buffer
-Messages produced within a transaction are stored in the transaction buffer. The messages in transaction butter are not materialized (visible) to consumers until the transactions are committed. The messages in the transaction buffer are discarded when the transactions are aborted. 
+Messages produced within a transaction are stored in the transaction buffer. The messages in transaction buffer are not materialized (visible) to consumers until the transactions are committed. The messages in the transaction buffer are discarded when the transactions are aborted. 
 
 ## Pending acknowledge state
 Message acknowledges within a transaction are maintained by the pending acknowledge state before the transaction completes. If a message is in the pending acknowledge state, the message cannot be acknowledged by other transactions until the message is removed from the pending acknowledge state.
 
-The pending acknowledge state is persisted to the pending acknowledge log. The pending acknowledge log is backed by a Pulsar Topic. A new broker can restore the state from the pending acknowledge log to ensure the acknowledgement is not lost.
+The pending acknowledge state is persisted to the pending acknowledge log. The pending acknowledge log is backed by a Pulsar topic. A new broker can restore the state from the pending acknowledge log to ensure the acknowledgement is not lost.