• Arcs appear in practically every animation since no object will operate in a straight line and will instead take an arc. Circular movement is known as arc.
• Humans do not move in a single straight line. They make arcs as they go. Similarly, the arc approach aids animation in creating the appearance of movement, such as the bouncing of the ball 
• In actual life, everything travels in an arcing manner. Because people don't move in straight lines naturally, you need stick to this animation technique to produce smooth, realistic movements. The flatter the arc and the wider the curve, the faster something moves. A robot is the only thing that could move in a completely straight path.

Read More: What is animation?