Which is the latest version of selenium testing tool?

The Selenium Server is needed in order to run either Selenium RC style scripts or Remote Selenium WebDriver ones.e.

2.47.1 is the lastest version of selenium

Selenium Latest Version

As of 03 Jan 2018, the latest version of Selenium WebDriver for Java is Selenium 3.8.1. This version of Selenium provides better support for GeckoDriver (which you would need to launch Mozilla Firefox). Before Selenium 3.8, there were other releases of Selenium 3, important ones being, Selenium 3.0beta releases and then Selenium 3.0, 3.1, 3.2 to 3.8.