Explain Transactions through data structures

[critesjosh]

On the Foundational Concepts Transactions page, we talk about the life cycle of a transaction, sequentially through time.

This can be confusing because it doesn't clearly lay out all of the nuances with the private / public execution separation and how private execution may fail during the public execution step.

The suggestion is to start at the Ethereum rollup contract and explain what data is validated there (a rollup block of data). How is that information validate? From there, take a step "back" and explain how the sequencer and the prover network builds a block and submits it to Ethereum.

• What information is included?
• How is it generated?
• Where does the sequencer get this information?

It is generated from users sending transactions. they receive proofs, commitments (note hashes), nullifiers, public inputs and public execution steps. Take another step back... how does a user generate this information?

Explaining transactions this way might be a nice complement to the information we already have on that page.

Another piece of feedback from Nico on-boarding