Arweave: pay once, store permanently
Arweave takes a different approach to decentralized storage than Filecoin's ongoing deal model. Rather than paying a provider periodically to keep renewing a storage agreement, Arweave is designed around a pay-once model, where a single upfront payment is meant to cover storage of the data permanently. This is made possible by an endowment-style economic model, where part of what you pay upfront is set aside to fund the cost of storing that data far into the future, so storage nodes on the network keep being incentivized to hold it long after the original transaction.
This makes Arweave a natural fit for data that genuinely needs to persist indefinitely and shouldn't require anyone to keep actively managing a subscription or renewing a deal, such as historical records, archives, or documents where the entire point is that they remain accessible decades from now.