MetaTrader 5 (MT5)
The dominant retail forex execution platform. Direct broker integration, built-in charting, expert advisors.
Most brokers default to MT5 (or older MT4). Execution, order management, and history tracking happen here. Good enough for trading, poor for charting - most traders chart on TradingView and execute on MT5.
Related
Learn to actually use MetaTrader 5.
Definitions are the easy part. The free first five modules put this on a real chart and make you do the work. No card required.