Adidas designs every World Cup ball, and on top of being a big seller for them, engineers at the company are constantly a little closer to the perfect ball, Goff says. The ideal soccer ball is a pimple-covered, perfect sphere, its surface just subtly textured enough to keep the airflow around the ball slightly turbulent. Unintuitive as this might sound, the ridges and pimples on the ball make it more aerodynamic, helping the ball to fly through the air more stably.
On the other hand, replicas (sometimes called training balls or gliders) are designed to be just like the official match balls but are much cheaper. Their panels are often stitched rather than thermally-bonded and are made of a different material. However, they’re not necessarily less durable than official match balls. So, they’re the recommended option for most players. https://www.youtube.com/watch?v=j2Xn84L3Kcs