What is an on-chain transaction?

An on-chain transaction takes place on a blockchain without the help of a second-layer protocol and remains dependent on the state of the blockchain to validate it. These transactions are only deemed valid when the blockchain updates to reflect a record of the transaction on the public ledger. 

Since they’re immutable and cannot be altered after they’re validated, these types of transactions offer security and transparency. However, depending on the blockchain and its network congestion, validations of transactions might not be instantaneous. That’s where second-layer protocols come in handy.  

On-chain transactions also come at a cost, which can fluctuate depending on how much transaction volume there is on the network.