The phrase "original blockchain" refers to the first and oldest blockchain technology called Bitcoin. It is the original method of recording and verifying digital transactions in a decentralized and secure manner. Full definition
Basically, if you want to create a blockchain application, you wouldn't have to build an entirely original blockchain base for it. (chainbits.com)
Contrary to conventional wisdom, the title of original blockchain belongs to bitcoin cash and not bitcoin, according to a recently published paper by the National Institute of Standards and Technology (NIST). (hacked.com)
Ethereum enables the development of potentially thousands of different applications all on one platform, instead of having to build an entirely original blockchain for each new application. (captainaltcoin.com)