A net, in its primary meaning, comprises fibers woven in a grid-like structure. It blocks the passage of large items, while letting small items and fluids pass. It requires less material than something sheet-like, and provides a degree of transparency. Examples include cargo nets, fishing nets, butterfly nets, cricket nets, bird netting or nets used in sporting goals in games such as soccer, basketball, Bossaball and ice hockey. A net also separates opponents in various net sports such as volleyball, tennis, badminton, and table tennis, where the ball or shuttlecock must go over the net to remain in play. Nets have been in use since primitive times, and the weaving of nets may be a precedent to basket weaving.