On occasion, you may notice that part of your wallet balance is temporarily locked. The reason behind it is complex, but let us offer a simplified explanation here. For more details, please refer to the whitepaper.
As you may know already there’s no such thing as account balance in the blockchain. Instead each wallet consists of inputs and outputs. Due to the nature of incoming transactions, the amount in a wallet balance can get fragmented. When you try to send a particular amount, your transaction will be split in outgoing and change amounts. Here is example.
Alice has 100 coins and sends 50 to Bob Transaction of 100 coins creates in the blockchain 50 coins goes to Bob and 50 coins goes to Alice
Zano architecture demands 10 confirmations for this change transaction and that amount gets locked in the wallet. Therefore, lock time is 10 blocks behind or approximately 10 minutes.