Do you mean market share?
OK, think of a market-let's say tablets.
Let's say 1bn tablets are sold globally each year and they are worth $300bn.
So that's 100% of the tablet market.
Let's say currently that Apple have 60% of that market (selling 60% of 1bn tablets) and Samsung have 35% and all the rest of companies making tablets have 5%.
Maybe one of the rest may be Lenovo.
They want to grab (increase) their market share and this will have to be at the expense of Apple or Samsung.
They would do this by making their tablet as good as or better than the competition, maybe a more competitive price or some 'must-have' novel feature.
It suggest an aggressive advertising/marketing campaign to get a significant number of sales of your product, If your company sells 25% of all Jelly Beans sold, you have a 25% market share.
I'm not completely sure what this concept means. Please explain in terms for someone who has never taken a business or economical class.