Margin, it's role(what does it do & how to use it) + advantages anddisadvantages

To be straight forward, margin is an instant loan which provides investors with more capital to increase their buying power. With more buying power you can invest more and potentially make more money than you would have without the margin. This is the good side to margin. The bad side to margin is that it inflates your losses so instead of losing 5% on your own personal money you could lose 5% of your money and the margin which makes it easier to become a non-profit trader lol. 

Margin is meant for traders who understand what they're doing and who will use it wisely. While trading we imagine we are only dealing with the money in our account but in reality you're handling much much more money so act like it. A fund manager managing a $1,000,000 trading account wouldn't place a $100k trade simply because that's the direction of the trend. That wouldn't be a responsible thing to do with such a good amount of money. If that manager had a large portion of the markets capital he would cause such catastrophic market disruption. Since we little people are restricted from such fun times do to capital restrictions... We cause disruption in our portfolios when we don't respect our position as traders using margin. 

So remember, when you're trading and ready to make a move, you're capital is more powerful than why's displayed on that screen. Be precise and sure when trading and use your capital wisely. Even that which you cannot see.