'Sketch' is a digital design toolkit and vector graphics editor, developed by Bohemian Coding, a Dutch company. Primarily, it's used for designing the user interface and user experience of websites and mobile apps, excluding print design features. Its simplicity and UI/UX design focus are key aspects of Sketch.

Since its debut in 2010, Sketch has become popular among designers, particularly for web and mobile app projects. It features a minimal interface and robust tools for creating precise and pixel-perfect designs, making it suitable for both novices and experienced designers.

Key functionalities of Sketch include vector editing, pixel precision, built-in grids and guides, and reusable elements known as symbols. It supports plugins for extended features and integrates with various tools and services.

Sketch stands out for its collaborative features, enabling teams to share, review, and iterate on designs efficiently. Its capability to export assets in multiple formats and resolutions positions it as a vital tool in contemporary web and app design processes.