The difference between Selenium and QTP are as follows:-
For browser-based testing, Selenium can very well be used.
There is an open-source tool Iris which does not cost anything.
You must need to have programming skills for using selenium.
You need quite a bit of expertise to learn Selenium.
Selenium does not come powered with several add-ins which you will get in QTP.
QTP is ideally suited for browser-based testing.
QTP has licensed therefore costs are quite a bit.
It is quite easy to learn and use when compared to selenium.
QTP comes powered with several add-ins and hence can work seamlessly with Web, Windows, Java and Dotnet application simultaneously.
You can take up the following Selenium Training Course to learn more about it. If you like reading then do read the following Selenium Tutorial. Here is the link of the video tutorial which you can watch to clear all your basics about Selenium. .