>>14115844A particle is anything with a definite start and a definite end. Things emit one frequency of light between a definite starting temperature and a definite ending temperature. That's a particle, called the photon. Planck modeled it as one container of length L with a hole and filled with oscillators. Similar models exist showing how things can interact by changing their mass while keeping their temperature the same, the weak force. And also the strong force, where you loose mass but your temperature goes up.
Energy in nature is quantized. You can't get half or thirds just like you can't pay for something with half a penny.
The wave like nature of light is due to things interacting with their internal configuration. The external properties like temperature or density, is due to an internal configuration that even it's external properties cannot figure out exactly. It's modeled as a wave to show this margin.
