A tooltip is a small “box” with information that will be displayed when you hover over an item on a web page. A tooltip is only meant for a small amount of textual information. If you want to use a “hover box” that can display more text and images a popover would be better.
If you have looked at the explanation in the Bootstrap 3 Tooltips section on their website and aren’t sure you understood all of it then this tutorial aims to clarify those issues. Tooltips appear simple by the look of them but you wouldn’t be the first to have questions about how to insert and style them.