A "tooltip" in web design refers to a small information display that appears when the mouse pointer is moved over a specific element, such as a button or a link. The tooltip provides additional information or explanations about the element without the user having to leave the page or open a new page.
An example of the use of a tooltip would be in an e-commerce shop that has a "More information" button for each product. When the user moves the mouse pointer over this button, a tooltip can appear showing more details about the product, e.g. size, colour, material or product description. The tooltip allows the user to obtain more information quickly and conveniently without having to leave the page.
Another example of the use of a tooltip is in a form with input fields. When the user moves the mouse pointer over a field such as "Password", a tooltip can be displayed that provides information on the input, e.g. that the password must have a minimum length of 8 characters or requires special characters.
The tooltip is a useful function in web design to provide additional information, help users navigate or provide context to certain elements without having to leave the page or being confronted with overloaded information.