L2 shows not only the current bid, and the last price traded, but also shows other bids and bidders.
This enables bigger players (aka market makers) to have a better idea where the pps is going.
Nearly every trading platform has a level 2 of some sort.
Gives alot more info, but there are fees attached, maybe higher commissions, or required amount of trades per month, or so on.
Vndm is one of those market makers, there are many of them.