Tooltip

A tooltip is a text box that appears next to the mouse cursor when hovering over certain elements in the user interfaces, or when switching the held item.

Item tooltips
When hovering over an item in the inventory with the mouse cursor, a tooltip with the item’s name will appear next to the cursor. Some items display extra information on their tooltips, such as enchantments and shulker box contents. Basic item tooltips are also visible in the "Items" section of the statistics menu when hovering over a block or item on the left side of the screen.

$$, advanced tooltips, including item IDs and the exact remaining durability of tools, can be displayed by pressing.

Held item tooltips
When switching the item being held, the name of the item appears above the hotbar. In Bedrock Edition, held item tooltips also show enchantments and shulker box contents.

Effect tooltips
When effects in the inventory are displayed in the compact style, hovering over an effect icon displays more information about that effect.

Option tooltips
When certain options are hovered over, they show a description in the form of a tooltip.

Trivia
The old tooltip design is still in use on the “Items” section of the statistics menu.