What is Wi Fi Connection and what is difference between the internet, bluebooth and wi fi?

There is no difference between the internet and wifi. Wifi stands for "wireless fidelity" and it just means you're using your internet connection without actually having the ethernet plugged into your computer, but into a router that will send the signal out to your laptop. Bluetooth is different, it can be used to access the internet but it's not a lot, it's más commonly used for file transfers and syncs between phones and hard drives.