'Scalping' can have various descriptions on whom you ask. Typically, 'scalping' is a spezialized technique that involves making a tiny trade to capture avery small movement in the marktet. Wheras a 'position trader' may engage in trades that are intended to last for multiple days to months and a 'day trader' typically enganges in trades that are intended to last for less than a day, a 'scalper' engages in trades that might only last a few minutes aiming for targets of about 5 pips.

A 'scalper' trades multiple lots, often more lots one would normally trade if trading as either a 'day trader' or a 'position trader' (simply due to the fact that those styles typicaly require larger stops thus shrinkung the amount of lots one can safely trade according to money management princicples). By trading more lots a 'scalper' can achieve significant gains comparable to the gains expected by day & position traders in the same time span even though the scalper engages in much smaller individual trades.

Yes, you're right. Finding the correct broker for scalping is some sort of a life-task. All Market Makers are definately not the right brokers for scalping.