Automation testing is boom now because IT industry is moving towards Automation completely which reduces repeated manual efforts.
There are various automation tools in the current trend like UFT, Selenium, protractor and now RPA. Most effective tool among these for UI automation is Selenium. Though UFT is in the race but selenium overtakes in terms of below points-
1. Selenium tool can be used with most of the scripting languages java,.net,python etc.
2. It is an open source tool means no need of any paid license so that small to big companies prefer it than UFT.
3. Most of the UI automation can be performed by selenium except some areas like CAPTCHA.
IT trend is always revolutionary, now selenium is leading the automation market after some days some new tool might rule the Industry.