A Word Ladder is a kind of puzzle in which one word must be transformed into another specified word of the same length by changing one letter at a time, each step yielding a valid intermediate word. 

Watch  the word SWING transform into the word FLIPS by changing one letter a the time:

swing→ swinE→ swiPe, sNipe→ sLips → Flips 

This short animation uses motion and typography based on the meaning of each word to illustrate the transition between words.