Lki Godet: Data could mean lots of things. The data that we're concerned about is thea state transitions, the transactions in the block. Light clients only follow the headers and only care of like transactions they care about,. But not every transaction. That's what foll notes do. And valid datus, down note the header and down note de state transitions, all of them. They also do note all the transactions. So they have have the transactions in their mempo. A fall node also down loads all the a, consensos messages, which are votes - essentially, a block proposel proposes a summary of the block; then their several rounds to get consensus on it