2D animation uses hand-drawed images, either being on a digital software or on paper, creating the width and height by themselves. 2D animation takes longer, as you have to draw each page and frame for the animation sequences. In comparison to 3D animation, you use only digital softwares for them, however it takes less time to animate, as you just have to insert keyframes for each of your frames, and the software automatically fills in the empty spaces within the beginning and ending points. In addition, 3D also adds more in depth with the object’s height and width, adding more realism within the animation.

https://study.com/learn/lesson/2d-animation-vs-3d-animation-differences-examples.html#:~:text=2D%20animation%20uses%20hand%2Ddrawn,realistic%20and%20three%2Ddimensional%20appearance.