A market order executes immediately at the best available price. You are saying: I want to buy or sell right now, and I accept whatever price the market gives me. The advantage is certainty of execution. The disadvantage is that you have no control over the price, and in thin markets, you might get filled at a price significantly worse than what you expected. This price difference between expected and actual fill is called slippage.
A limit order specifies the maximum price you are willing to pay (for buys) or the minimum price you are willing to accept (for sells). The order will only execute at your specified price or better. The advantage is price control. The disadvantage is that your order might never fill if the market does not reach your price. A limit order to buy BTC at $60,000 when the market is at $65,000 will only fill if the price drops to $60,000.
Stop orders trigger a market order when a specified price is reached. A stop-loss order to sell at $60,000 will become a market sell order when the price hits $60,000. The purpose is typically to limit losses on an existing position. The catch is that stop orders become market orders once triggered, so in fast-moving markets, your actual fill price might be significantly below your stop price.
Stop-limit orders combine the trigger mechanism of a stop order with the price control of a limit order. When the stop price is reached, instead of a market order, a limit order is placed. This gives you price control but introduces the risk that your order never fills if the market moves through your limit price too quickly. In a flash crash, a stop-limit might not execute at all, leaving you exposed.
Trailing stop orders adjust automatically as the price moves in your favor. A trailing stop set at 5% below the current price will follow the price up, always staying 5% below the highest point reached. If the price then drops 5% from its peak, the stop triggers. This mechanism lets profits run while providing a dynamic exit point. The challenge is setting the trailing distance, too tight and normal volatility stops you out, too wide and you give back too much profit.
Take-profit orders are limit orders placed to close a position at a target price above (for longs) or below (for shorts) your entry. They automate the process of locking in gains at predetermined levels. The tradeoff is that you might exit too early if the move continues beyond your target. Many traders use scaled take-profits, closing a portion of their position at each of several target levels.
Post-only orders guarantee that your order will be placed as a maker order (adding liquidity to the book) rather than taking liquidity. If your limit order would immediately match with an existing order, it gets cancelled instead of executed. This is useful because maker fees are typically lower than taker fees, and on some exchanges, makers actually receive a rebate. The disadvantage is that your order might be repeatedly cancelled in fast-moving markets.
OCO (one-cancels-other) orders link two orders together so that when one executes, the other is automatically cancelled. A common setup is linking a take-profit limit order with a stop-loss order. Whichever one fills first cancels the other. This automates the complete management of a position without requiring you to monitor it constantly.
For most traders, mastering limit orders and stop-losses is sufficient. Use market orders only when you need immediate execution and the spread is tight. Use limit orders for entries when you are willing to wait for a better price. Use stop-losses on every position to define your maximum risk. Everything else is refinement that helps in specific situations but is not essential for solid trading.