I'm reading some posts with mentions to SPV and other types of clients and I keep forgetting what the initials mean so doing a little bit of research this is what I found.
SPV client - Simplified Payment Verification Client: A lightweight Bitcoin client that downloads only part of the blockchain
https://en.bitcoin.it/wiki/Scalability#Simplified_payment_verificationI didn't find them in the initial post so you may want to include them