I don't know much but this is what I read about it :Layer three protocols, commonly known as application layers, consist of the protocols that allow applications to run on blockchains, as well as the applications themselves. ... For example, when a user initiates a transaction, the process moves from the application layer to the execution layer.
I still have to grow my infos on this

Layer 3 Protocols

Layer three protocols, commonly known as application layers, consist of the protocols that allow applications to run on blockchains, as well as the applications themselves. These are the thin protocols discussed earlier.
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