Simplified Payment Verification (SPV)
The phrase “Simplified Payment Verification” (SPV) refers to software that checks other nodes for new blocks and transactions but does not maintain the blockchain itself, unlike a node. A type of light client that Satoshi Nakamoto describes in the whitepaper is an SPV client.
With SPV, users will have access to a trust-minimized method of exploring the blockchain without having to deal with the hassle of maintaining a node. The nodes that SPV clients use to query the blockchain are trusted, but there are many more nodes and the cryptographic security of Merkle trees that make it very difficult to misuse this trust.