Concepts
Why does Portal Network exist?
Portal is an important way to support the evolution of the core Ethereum protocol.
To relieve pressure on Ethereum clients, the core protocol will allow full nodes to forget old data in a likely future upgrade.
When that happens, the Portal Network can supply users with that purged data.
How do Portal clients use less space?
Each Portal Network client stores a user-configurable fraction of the data. The client retrieves any missing data from peers, on demand. Just like a full node, the client can cryptographically prove the data it serves.
flowchart TB subgraph Full node data: on one computer full[Regular full node] end subgraph Full node data: spread amongst computers p1[Portal node] p2[Portal node] p3[Portal node] p1 <--> p2 p2 <--> p3 p1 <--> p3 end