What do you call SPV wallet ? Sorry but it is the first time i hear about it
Any wallet that isn't a full node.
Then what do you call Bitcoin Core with pruning turned on?
It isn't a "full node" since it can't supply the blockchain to any other bootstrapping node, but it does full validation of transactions, so it isn't a Simplified Payment Verification (SPV) node either.
According to the original Bitcoin Whitepaper (written by Satoshi), a SPV node is a node that:
only needs to keep a copy of the block headers of the longest proof-of-work chain, which he can get by querying network nodes until he's convinced he has the longest chain, and obtain the Merkle branch linking the transaction to the block it's timestamped in. He can't check the transaction for himself, but by linking it to a place in the chain, he can see that a network node has accepted it, and blocks added after it further confirm the network has accepted it.
As such, the verification is reliable as long as honest nodes control the network, but is more vulnerable if the network is overpowered by an attacker. While network nodes can verify transactions for themselves, the simplified method can be fooled by an attacker's fabricated transactions for as long as the attacker can continue to overpower the network.
It seems there are at least 4 types of wallets:
- Full node wallets (Wallets that validate AND store the full blockchain making it available to other nodes). Example: Bitcoin Core
- Fully validating wallets (Wallets that receive and process the entire blockchain building and storing their own UTXO, but not storing the majority of the blockchain and therefore not useful to bootstrapping other nodes). Example: Pruned Bitcoin Core
- SPV wallets (Wallets that keep only the block headers of the longest chain and the merkle branches of transactions to or from the wallet, requiring trust in the full nodes it is connected to). Example: MultiBit
- Client wallets (Wallets that maintain only the private keys and must connect to a trusted server (or service) that provides the necessary transaction information). Example: blockchain.info