What is Trader Workstation (TWS) ?
TWS is a Java based application for Windows, MacOS and Linux to trade an Interactive Brokers (IBKR) account.
Do i need to install Java ?
No. TWS comes with its own Java runtime.
What is the difference to Gateway ?
The Gateway is a slim application for the purpose only to connect so called API clients to IBKRs backend. It is not possible to manually place orders or to retrieve account data, etc. Just a gateway for API clients.
An example for an API client is our MetaTrader Interactive Brokers Order Copier