The brokerage and exchange differ with regards to who you are buying or selling crypto assets with.
On the brokerage, you buy or sell crypto assets with a Virtual Asset Service Provider (VASP) as the other party. The benefit is that you can immediately buy or sell crypto assets whenever you please; however, the VASP sets the prices for buying or selling each crypto asset. This causes spread (the difference between the buy and sell prices), which is essentially the transaction cost. As a result, it may feel more expensive.
On the exchange, you buy or sell crypto assets with other LINE BITMAX users. There is no spread, but you pay a fee to the VASP for each transaction. Also, as opposed to the brokerage, you may not be able to complete your desired trade due to board conditions.
Note: LINE Xenesis may place orders as a trader to improve exchange liquidity.