What is MQL5

MetaQuotes Language 5 (MQL5) is a built-in language for programming trading strategies, developed by MetaQuotes Software Corp
MQL5 contains a large number of functions necessary for analyzing current and previously received quotes, and has built-in basic indicators and functions for managing trade positions and controlling them. Using this language, you can create your own Expert Advisors that make trading management automated and are perfectly suitable for implementing your own trading strategies. Besides, using MQL5 you can create your own technical indicators (custom indicators), scripts and libraries.

MQL5 Features :

• Expert Advisor: Are stored in terminal_directory\MQL5\Experts.
  Expert Advisor will starts running if there is a trigger or event.
  The kind of event could be :
  - When initialization or deinitialization,
  - When a new tick receipt,
  - On timer event
  - On market changing event,
  - Base on chart event, and custom events.
  With EA user can trade automatically (execute/send/cancelling) order to the broker server.
• Custom Indicator: Are stored in terminal_directory \MQL5\Indicators
  Behavior of custom indicator is running independently and can not trade automatically. Custom indicator is made if built-in indicators is not suit user need.
• Script: are stored in terminal_directory\MQL5\Scripts
  Script is a program intended for a single execution of some actions.
• Library: are stored in terminal_directory\MQL5\Libraries
  Library is a set of custom functions that frequently used by custom programs. Libraries cannot start executing by themselves, they have to be call from program.
• Include File: are stored in terminal_directory\MQL5\Include
  Include is a source text that can frequently used by programs. It can be included into the source texts of Expert Advisors, scripts, custom indicators, and libraries at the compiling stage. Include files also can be stored in the same directory as a source file. User

Tools: MQL4 to MQL5 converter
Migrate from MQL4 to MQL5