FPS - (frames per second) the number of frames (drawings) displayed in one second, the higher the frame rate, the smoother the video

Frames - a single picture or drawing that is a part of a movie, video, or animation

Underlay - 

Animating on the Ones, Twos and Threes - animating using a new drawing for every frame (ones), every second frame (twos), or every third frame (threes)

Scenes - 

Panels - 

Storyboard - the planning of a story organized with scenes and panels

Animatic - a storyboard but with simple animation to show character and object movements

Persistence of Vision - multiple images blending in together to create the illusion of movement