Normally in trading orders are known as act to express buying or selling intention in market. Those intentions may be price specified or time specified. And in some cases orders are may be on market conditions. So basically when a trader is placing his/her intention to buy/ sell any listed contract shall be placing his intention in 3 ways: market conditions, price specified and time specified.

Market orders:

Market orders are known as market condition order. Once a trader is placing and confirming his/her intention to buy or sell any listed contract to buy/sell on market condition it will get highest priority for execution. On best available anonymous bid/offer it shall get executed. While placing such orders trader is selecting only contract and unit to buy and sell on market price. When order reaches on server after validating all security and financial checks order will get executed on available price which is available at that moment on market. As in this type of order trader doesn’t wish specify price and doesn’t specify any time limit for execution. Due to this nature of order it’s known as market condition order.

Price specified orders:

Any orders that are placed on system to get executed on specified price level reach known as price specified orders. Price specified orders are normally known as stop order and limit order.

Stop order:

A stop order, also referred to as a stop-loss order, is an order to buy or sell a contract once the price of the contract reaches a specified price, known as the stop price. When the stop price is reached, a stop order becomes a market order. A buy–stop order is entered at a stop price above the current market price. Investors generally use a buy stop order to limit a loss or to protect a profit on a contract that they have sold short. A sell–stop order is entered at a stop price below the current market price. Investors generally use a sell–stop order to limit a loss or to protect a profit on a contract that they own.

While placing stop order trader wish to specify price level to enter in market.

Limit order:

A limit order is an order to buy a contract at no more than a specific price, or to sell a contract at no less than a specific price (called "or better" for either direction). This gives the trader (customer) control over the price at which the trade is executed; however, the order may never be executed ("filled"). Limit orders are used when the trader wishes to control price rather than certainty of execution.

While placing limit order trader wish to specify price level to enter in market.

Time specified orders:

Time specified orders are also expressed on form of limit or stop order. But the difference with this category of order trader wishes to continue his/her specific order for certain time frame. Those time frame is available to select on system so trader can specify for the day, week or till contract expiry.

Normally time specified orders are divided in following categories:

Good for day or day order: any limit or stop order is placed in system with selection of day order is known to be valid till day closing of market. Once day closing occurs such unmatched orders shall be flushed out from central order book and the validity of such orders are known as expired according to specified time.

Good till Friday: any limit or stop orders those are placed with GTF selection means such orders are valid till weekly closing of market. As Friday is known as weekly closing of market worldwide so it’s known as valid till weekly closing of market. Any unmatched orders shall be treated as expired and invalid to carry forward for next week opening of market.

Good till cancel: Good-Till-Cancelled (GTC) order is an order to buy or sell a contract that lasts until the order is completed or cancelled till expiry of contract.