Polyhydroxybutyrate (PHB) is a type of biodegradable plastic made from renewable resources. It is produced by certain bacteria as a way to store energy. PHB is part of a larger group of materials known as polyhydroxyalkanoates (PHAs), which are gaining attention for their environmentally friendly properties. PHB can be used in various applications, including packaging, medical devices, and agricultural films. Its biodegradability makes it an attractive alternative to traditional plastics, as it breaks down naturally in the environment, reducing pollution and waste.