Quasiparticles are collective excitations that arise in many-body systems, behaving like particles even though they are not fundamental particles themselves. They emerge in various contexts, such as in solids, liquids, and gases, where interactions between particles lead to new effective behaviors. Examples include phonons, which represent sound waves in a material, and magnons, which describe collective spin excitations in magnetic systems. These entities simplify the complex interactions in a system, allowing physicists to use particle-like models to describe phenomena. Quasiparticles can carry energy and momentum, making them essential for understanding various physical properties, including superconductivity and quantum fluids.