A soccer ball is a sphere of leather or similar material filled with air based on the specifications given by FIFA. Here are the basic requirements for an official soccer ball:
The ball must have a circumference of 68-70 cm. The ball must have a dry-weight between 410-450 grams since older balls with weather exposure tend to be slightly heavier. It must be inflated to a pressure of 8-12 psi and made of leather or another suitable material. There are different sizes os soccer ball, with the size 5 being the official standard. Other sizes are for different sports like futsal and handball.
The ball has a very big influence on a game. FIFA specifies everything about a ball except for its aerodynamics. FIFA does not say anything about a ball should travel in the air and how far it should go. The belief is that a different characteristic of a ball will apply to both teams and should not favor one over the other. Different shapes affect how the ball moves, with the latest 14-panel designs favoring outfield players. Some players master the art of kicking the ball with minimal spin, letting the panels on ball affect the air-flow in unpredictable ways, making it impossible for keepers to predict flight.
Most research and development goes into how the shape and materials of the ball. However, the latest design of the Adidas ball includes the latest Goal Line Technology. Built with robust materials and a special magnetic field, you can track the ball and tell exactly when the entire ball crosses the line, making the life of the referee much easier.