For most of blockchains you can do light client validation without the full chain (or full node). Light client needs to only know the block headers to validate

For most of blockchains you can do light client validation without the full chain (or full node). Light client needs to only know the block headers to validate a truth. You can get block headers with very lightweight download work from peer-to-peer network. https://geth.ethereum.org/docs/interface/les https://geth.ethereum.org/docs/interface/les