Use components to build interfaces. Search the component's name in the Component panel (Shift + A) or use quick search (Ctrl + E). Once you added a Component to your page unlink it to make changes. Right-click on the symbol’s label and choose unlink from symbol. This is the rule. We use overrides only as an exception for simple components that you'd rather want to re-style on the specific page within Style Guide (buttons, toggles etc. - mostly atoms).
Tooltips identify elements or provide additional, useful information about the referring elements. Tooltips are different from ALT-attributes, which are intended primarily for static images. Tooltips fade in upon hover or touch of its trigger element. They fade out upon interacting with an area or element outside of the tooltip or its trigger, or on a delay of the cursor moving outside the tooltip or its trigger element.