As the Texture tool has several keypresses which can add or change its functionality, we suggest installing the free Astute Graphics plugin Astute Buddy, which creates a panel that dynamically updates to inform you of the various keys which can be pressed in the tool’s current context.
The Texture tool allows a Texture live effect’s parameters to be changed using an on-screen, annotated widget. All selected art objects with Texture live effects will display this widget (centered above the art’s bounding box) when the Texture tool is active, but only one of them will be “targeted” and displayed in color (red, by default) rather than gray. This texture is indicated on the Texture panel as the “current” texture.
Texture Targeting Annotations