Final answer:
The feature in Photoshop that manages libraries of creative assets such as brushes and swatches is known as the Presets Panel or Presets Manager.
Step-by-step explanation:
The Photoshop feature that allows you to manage libraries of preset brushes, swatches, gradients, styles, patterns, contours, custom shapes, and tools is known as the Presets Panel or sometimes the Presets Manager, depending on the version of Photoshop being used. This panel provides a streamlined and organized interface for users to quickly select and utilize various creative assets in their projects. For instance, digital artists can use the brush presets to apply different brush strokes to their artwork, while graphic designers might use swatch presets for consistent color management across their designs.