Order/Execute an order

01:20 Dec 21, 2015 

Matching: http://www.investopedia.com/terms/m/matchingorders.asp
The process for executing securities trades by pairing buy orders with sell orders. Matching orders utilize algorithms which determine how orders are matched and in what order they are filled, which subsequently differ based on the venue to which the trade is routed. One common algorithm used in matching orders utilizes first in, first out (FIFO), which prioritizes assets acquired first to be filed for selling first.

Execution: http://www.investopedia.com/terms/e/execution.asp
BREAKING DOWN 'Execution'
Brokers are required by law to give investors the best execution possible, and can attempt to execute the transaction in the following ways:

1. Order to the Floor: This can take some time as it goes through human hands. The floor broker will need to get the order and fill it.
2. Order to Market Maker: On exchanges such as the Nasdaq, market makers are in charge of different stocks. The investor's broker may direct the trade to one of these market makers for execution.
3. Electronic Communications Network (ECN): An extremely quick method, whereby computer systems electronically match up buy and sell orders.
4. Internal