What is free margin on Kraken?

I'm curious about the concept of free margin on Kraken, could you please elaborate on what it means? As someone who's new to the world of cryptocurrency trading, I'm eager to understand how this term fits into the overall trading strategy and how it can affect my trading outcomes. Is free margin a reflection of my trading account's available funds for further trades, or does it have a different significance? Additionally, how does Kraken's approach to free margin differ from other cryptocurrency exchanges, and what are the potential risks associated with managing my free margin effectively?