trader - broker-dealer

whats the difference between these 3? getting somewhat confused by the multitude of Qs on this section. thanks.

trader is the investor who is looking to execute the trade. Broker is someone who is helping the trader to find other side of the tradeā€¦earn a commission. Dealer is providing the liquidity to the trader from its own inventory or using its own capitalā€¦earns a mark up or mark down.