What's the difference between B$2$C and B$2$B marketing?

B$2$C is business$-$to$-$contract and B$2$B is business$-$to$-$bystander

B$2$C is back$-$to$-$concepts and B$2$B is back$-$to$-$basics

B$2$C is basically to consumers and B$2$B is basically to businesses

$B2C$ is business$-$to$-$consumer and B$2$B is business$-$to$-$business