Nonlinear animation is a type of animation that is not created in a linear fashion, meaning that the animator can work on any part of the animation at any time. This is in contrast to linear animation, where the animator must work on the animation in a sequential order, from beginning to end. Nonlinear animation is often used for complex animations that require a lot of back-and-forth editing.
Blender is a free and open-source 3D animation software that is popular for its powerful features and user-friendly interface. Blender can be used to create both linear and nonlinear animations, and it offers a variety of tools that make it easy to edit nonlinear animations.