They both are really two different things. QTP / UFT is a full-features software testing tool that includes test management, test planning and test automation.
Whereas Selenium is not a testing tool, it’s a set of APIs that allows you to control a browser with code. In its purest form Selenium has no test management, test planning or test analysis ability. Those have to be provided by the testing tool that uses Selenium as its test automation engine.
Talking in short about Selenium, it is fast-replacing UFT in businesses that are undergoing digital transformations and have a slew of web and mobile apps that they need to test. Where Selenium doesn’t play is in the test automation of Windows desktop applications. The selection of the best testing tool for you is an important decision. You should first understand what you need before you settle on a testing tool. For your reference, I am mentioning the following Selenium Tutorial which will help you choose the right one among them. You can also watch the below-mentioned video tutorial which I followed to know this answer. .