@bahesh Please don’t throw every possible tag on your topics. It’s incredibly important you choose only what is applicable for you. In this case, you tagged every single operating system. So unless your one device that’s having this issue is some hybrid that is part Windows, Android, Mac, Linux, and iPad/iPhone then you aren’t helping us to help you.
To clarify, Mac and Windows can do the same function but they are different button commands. I’m not sure about Linux. And that cursor shouldn’t be seen on iPhone, iPad, or Android.
All of that said, on Windows you hit F7 to toggle that on or off.
On Mac, you need to hit Fn+F7
This is the toggle for what is called caret browsing. Its purpose is to serve as a placeholder for what you’re reading, but it also helps give more control over things like highlighting words and all.