Types Of Orders

Some orders can specify time conditions

Market

These are the most common
This must be executed immediately and at the best price available in the market

Limit

Buy or sell at a specific price (or better).
This specifies a particular price and which either a maximum price to pay or a minimum price to sell.
There is of course no guarantee that the order will be executed at all
This means that shares are bought or sold if and only if they are within the limits.
May buy or sell some shares but not all of them.
Also called a Good till cancelled order or open order.

All or None - This means only buy or sell the shares if you can get the correct Quantity
Fill of Kill - This means only buy or sell the shares immediateloy if you can get the correct Quantity
A limit order to buy at $80 means buy it once it reaches $80 or less
A limit order to sell at $80 means sell it once it reaches $80 or more

Stop

Buy or sell when its price reaches a specific level.
This specifies a particular price which must be reached before finding the best price available.
A stop order becomes a market order as soon as the specified price has been hit.
Also called a stop-loss order.

Stop-Proft -
Buy - used to protect profits, vunerable to short-term fluctuations
Sell - used to avoid further losses

Stop-Limit - Combination of a stop order and a limit order
A stop order to buy at $80 means buy it at the best price once it reaches $80
A stop order to sell at $80 means sell it at the best price once it reaches $80

Market if Touched

This is executed at the best available price after a trade occurs at a specified price. Often called a "board" order

Discretionary

This is traded as a market order except that execution can be displayed at the broker's discretion in an attempt to get a better price. Often called a "market-not-held" order