The Bootstrap autocomplete component predicts entered words based on the first letters given by the user. You can search the list using basic scrolling and keyboard arrows.
It uses the default Dropdown component from Bootstrap 4 to create the list of autocomplete items.
When you use autocomplete on a texfield (also known as input type="text"), this library creates a Dropdown around it, with the parent as the container. When the length of the text written is equal to or larger than the treshold, a onkeyup event is injected into the textfield, triggering the Dropdown. After that, the data is filtered to show just the items that contain the inputted text. When you activate one of the items, the value of the textfield is set to the label of that item.