The "data management" family contains which four patterns, and what question do they collectively answer?

Encrypting On-Chain Data, Tokenisation, Off-Chain Data Storage, and State Channel — together they answer "what data goes on-chain, in what form, and what stays off?"

Storage on a blockchain is scarce (full replication), public (no privacy by default), and permanent (immutable). The four data-management patterns each take a different cut at living with that:

• Encrypting on-chain data — keep data on-chain but confidential, by encrypting before writing.
• Tokenisation — represent a transferable asset as an on-chain token.
• Off-chain data storage — keep bulky data off-chain, anchor only its hash on-chain for integrity.
• State channel — keep high-frequency or tiny updates off-chain entirely, settling only the net result on-chain.

Two of them (encrypting, tokenisation) put data on the chain in a safer form; two (off-chain storage, state channel) keep data off the chain while still leaning on it for a guarantee.