Dispersion:
Dispersion is the phenomenon of splitting light into its component colors. When white light passes through a prism or a water droplet, it undergoes dispersion and separates into a spectrum of colors. This phenomenon occurs because different colors of light have different wavelengths and speeds.

Prism:
A prism is a transparent object with flat, polished surfaces that can refract light. When white light enters a prism, it is refracted (bent) at different angles depending on its wavelength. The shorter wavelengths (violet and blue) are refracted more than the longer wavelengths (red and orange), resulting in the separation of colors.

Spectrum:
The spectrum is the range of colors obtained after white light undergoes dispersion. It consists of seven colors: red, orange, yellow, green, blue, indigo, and violet (ROYGBIV). Each color in the spectrum corresponds to a different wavelength of light, with red having the longest wavelength and violet having the shortest.

Rainbow:
A rainbow is a natural phenomenon that occurs when sunlight is refracted, reflected, and dispersed by water droplets in the air. It appears as a circular arc of colors in the sky, with red on the outer edge and violet on the inner edge. Rainbows are formed when sunlight enters water droplets and undergoes dispersion, creating the spectrum of colors.

Splitting:
Splitting refers to the separation of white light into its component colors during dispersion. It is the process by which the different wavelengths of light are spread out and become visible as distinct colors. This splitting is achieved through the refraction and dispersion of light as it passes through a prism or other mediums.

In conclusion, the splitting of white light into seven colors is called dispersion. This phenomenon occurs when white light passes through a prism and is refracted, resulting in the separation of colors into a spectrum. The spectrum of colors observed during dispersion is commonly seen in rainbows, where sunlight is dispersed by water droplets in the atmosphere.