Metatrader or MT4

DEFINITION of Metatrader or MT4

Metatrader or MT4 is an electronic trading platform widely used by online retail foreign exchange speculative traders.

WHAT IT IS IN ESSENCE

Posing similarly as a connecting channel between currency trading systems and your computer (or mobile device), and so MetaTrader is the link.
MetaQuotes Software was a developer and it released in 2005. The software has the license to foreign exchange brokers who provide the software to their clients.

The software consists of both a client and server component.

The broker is running the server and the client software is in service to the customers. They use it to see live streaming prices and charts, to place orders, and to manage their accounts.
The client terminal includes a built-in editor and compiler with access to a user-contributed free library of software, articles, and help. The software utilizes a proprietary scripting language, MQL4/MQL5, which enables traders to develop Expert Advisors, custom indicators and scripts.

HOW TO USE

MetaTrader’s popularity largely stems from its support of algorithmic trading.
MT4s’ utilization is a stand-alone system. But the broker has to manually manage their position. And this is a common configuration used by brokers.
MetaTrader provides two types of trading orders, Pending Orders and Market Orders. Pending orders will be complete only when the price reaches a predefined level. Whereas Market orders will be complete in one of the four modes. 

Instant Execution, Request Execution, Market execution, and Exchange execution.

The client is a Microsoft Windows-based application that became popular mainly due to the ability for end users to write their own trading scripts and robots that could automate trading. In 2010, MetaQuotes released a successor, MetaTrader 5. But, uptake was slow and as of April 2013, most brokers still used MT4. While there is no official MetaTrader 4 version available for Mac OS, some brokers provide their own custom developed MT4 variants for Mac OS.
Both platforms include apps for mobile devices as well as Windows.