A residual image is an optical phenomenon that causes the brain to continue to perceive an image. Even when its exposure to the eye is over.
Tweening is a computer-assisted animation technique. It consists in moving or morphing a digital element between 2 keyframes. This by using an animation software.
Pixilation is a frame by frame animation technique wich is similar to stop-motion Animation, but has the particularity to stage real people. So, just like stop-motion, the process consist to capture a series of photos, using a video camera or a photo camera.
Rotoscoping is a method used in animation that consists of tracing the contours of a filmed image and to transpose it into drawings. So we retrace the contours image-by-image of a filmed sequence in order to preserve the photorealism of the shot.
Cut-out animation is an animation technique in which pre-cut elements of the desired shape are moved frame by frame to recreate the illusion of movement.
Stop motion is an animation technique in which we will use inanimate "objects" that we will move image-by-image in space in order to recreate the illusion of movement.
Traditional animation is an animation technique that consists to give the illusion of movement by projetting a series of drawings in front of our eyes.
The 12 basic Animation Principles where created and described in the reference book for animators : "The illusion of life". This book was co-written by 2 top 2D Disney animators