Off blockchain transactions

A number of consumer-based bitcoin companies are focused on off-block chain transactions, including Coinbase, Circle Internet Financial.

These companies are facilitators of everyday payments between parties and, as a result, they have decided to keep transaction speeds high by keeping most payments internal – that is, off the the public block chain...

Simply, it's faster to use Coinbase-to-Coinbase, for example, than relying on Coinbase-to-block chain. Plus, "issues arise with miner fees," Robinson noted.

Transaction off the block chain do not incur the small amount of BTC that miners are paid for their services in verifying the ledger. Hence, transaction are a little more expensive on-chain.

[1] https://www.coindesk.com/block-chain-transactions-bad-bitcoin/