Image Credit: Disney via Creative Bloq
A series of images placed in a sequence; when played back, they give the illusion of a moving image. Generally animations are 30 frames per second. This means there are 30 individual images per every 1 second of animation. That means a 30 second animation has 900 frames!
Further reading: https://www.studiobinder.com/blog/what-is-animation-definition/