Photons are really interesting little things in the world of quantum physics. They show us something cool called wave-particle duality. This means that photons can act like both waves and particles.

1. Wave Behavior: When we look at light, we often see it working like a wave. For example, when light goes through small openings, it forms patterns as if it were waves in water. This is called an interference pattern, and it happens because the tops (peaks) and bottoms (troughs) of the waves mix together.

2. Particle Behavior: On the other hand, photons can act like small particles, especially when they transfer energy. A good example of this is the photoelectric effect. In this process, light can knock out tiny particles called electrons from a material. This shows that light comes in small packets of energy known as "particles."

You can think of photons as tiny messengers that carry energy. The amount of energy a photon has is connected to its frequency (how fast it oscillates). We can write this relationship with a simple equation:

$E = h f$

Here, $E$ stands for energy, $h$ is a constant named Planck’s constant, and $f$ represents frequency.

In short, photons show us that light and matter have a complex nature. They are important for understanding quantum theory and how the universe works at a small scale.