MetaTrader, a popular trading platform developed by MetaQuotes Software, has seen several versions over the years, each offering a range of features and improvements. As of my last knowledge update in January 2022, here's an overview of the different versions of MetaTrader:

1. MetaTrader 4 (MT4):
- Released in 2005, MT4 quickly became one of the most widely used trading platforms in the world.
- It offers a user-friendly interface, advanced charting tools, technical indicators, and automated trading capabilities through Expert Advisors (EAs).
- MT4 supports trading in multiple financial markets, including Forex, CFDs, and futures.

2. MetaTrader 5 (MT5):
- Released in 2010, MT5 is the successor to MT4 and offers several significant improvements.
- It allows trading in a wider range of financial instruments, including stocks and commodities, in addition to Forex and CFDs.
- MT5 offers more timeframes, technical indicators, economic calendar integration, and enhanced charting tools.

3. MetaTrader 4 and 5 Web:
- Both MT4 and MT5 have web-based versions, allowing traders to access their accounts and trade from any web browser without the need for software installation.

4. MetaTrader 4 and 5 Mobile:
- MetaQuotes offers mobile apps for both MT4 and MT5, enabling traders to stay connected and manage their positions on smartphones and tablets.

5. MetaTrader Supreme Edition:
- This is a plugin developed by Admiral Markets that extends the functionality of both MT4 and MT5. It includes additional indicators, expert advisors, and tools for risk management.

6. MetaTrader 4 and 5 Multi-Terminal:
- These versions are designed for money managers and traders who need to manage multiple accounts from a single interface.

It's important to note that the financial technology industry is continually evolving, and new versions or updates of MetaTrader may have been released since my last knowledge update. Traders and brokers may choose the version that best suits their needs based on the specific features and asset classes they wish to trade. Whether you are a novice or an experienced trader, MetaTrader's various versions provide a robust platform for market analysis and execution of trading strategies. Be sure to check for the latest developments and features in the MetaTrader ecosystem to make an informed choice for your trading activities.

There are several ways traders can use MetaTrader, although MT4 and MT5 are the primary versions. MetaTrader 4 remains highly popular among forex traders because it combines an easy-to-use interface with powerful charting tools, indicators, and automated trading through Expert Advisors. MetaTrader 5 is the more recent version and was developed with broader market functionality in mind. Where supported by brokers, it can provide access to forex, stocks, futures, and other financial products. MT5 also includes additional timeframes, order types, analytical tools, and improved backtesting features.

MetaTrader is not limited to desktop applications. WebTrader enables traders to access their accounts through compatible web browsers, making it convenient for users who do not want to install software. Mobile applications for Android and iOS provide another option for monitoring markets and managing trades from mobile devices. While both MT4 and MT5 are powerful platforms, traders should compare their broker support, available instruments, trading tools, and automation requirements before choosing one.