All terms
The guarantee that transaction data was actually published for anyone to read.
A rollup is only secure if its data is available. If the operator posts a state root but hides the underlying transactions, nobody can verify or challenge it, and nobody can reconstruct their balances.
This is the largest cost a rollup faces, which is why dedicated data availability layers exist.
Celestia and EigenDA sell cheap data availability so rollups can cut their biggest expense.
Where to go next
More technology terms
Want this explained out loud?
Some of these land faster in conversation than in writing. Sessions are one to one and you can ask anything, including the things that feel too obvious to ask.