Infragistics Ignite UI is a collection of user interface (UI) components designed for building modern web applications. It provides a wide range of customizable controls, such as grids, charts, and input elements, that help developers create responsive and interactive user experiences. The toolkit supports popular frameworks like Angular, React, and Vue, making it versatile for various development environments. Additionally, Ignite UI offers features like data visualization, theming, and accessibility support, ensuring that applications are not only visually appealing but also functional and user-friendly. With its extensive documentation and community support, developers can easily integrate these components into their projects.