Simplified Payment Verification or SPV, is defined as software that allows you to confirm a cryptocurrency transaction has been added to the blockchain without having to download the entire blockchain which is larger than 100 gigabytes in size.
Bitcoin transactions are kept on a digital record, known as the blockchain, and it is maintained by thousands of people around the world. This digital record is growing larger every day and in 2016, it exceeded 150 gigabytes.
Because it isn’t easy or fast for everyone to download the entire blockchain just to be able to send and receive bitcoin, simplified payment verification was made. SPV is included in some bitcoin wallets like Electrum with it, you can manage your own bitcoin in a much smaller software package.