With respect to the blockchain, almost all of the technology is available before bitcoin, but no one thinks it works until bitcoin, so bitcoin is the first successful application of blockchain technology. To the extent that bitcoin is the first blockchain there's nothing wrong with it. If you want to understand the blockchain technology, Bitcoin is indeed a thing that can't go around.
Maybe expert more understand what the realation betwen these two thing.
Simply, i think bitcoin is the working in blockchain technology and the product names bitcoin and the technology names blockchain.
Sorry if i can not explain well.