A server-side order lives on the broker's trade server: once accepted, a stop-loss, take-profit or pending order is monitored by the broker and still triggers if your computer, internet connection or terminal goes down. A client-side order exists only inside the platform or a script, which must stay running and connected for the exit to be sent. In MetaTrader the standard stop-loss and take-profit levels attached to a position are server-side, whereas virtual or hidden stops managed by an Expert Advisor, and many trailing-stop implementations, are client-side. The difference matters most during outages, fast news moves and weekend gaps, which is why risk plans usually rely on server-side protective orders where the platform supports them.
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How to Tell Who Is on the Other Side of Your Trade
Your counterparty is a fact about your account, not a mystery. The documents that name it, what each one adds, and the claims about order flow that nobody outside the firm can check.