### Instruction:
Given this paragraph about Mass–energy equivalence, tell me what each part of the equation E=mc² stands for.

### Input:
The formula defines the energy E of a particle in its rest frame as the product of mass (m) with the speed of light squared (c2). Because the speed of light is a large number in everyday units (approximately 300000 km/s or 186000 mi/s), the formula implies that a small amount of "rest mass", measured when the system is at rest, corresponds to an enormous amount of energy, which is independent of the composition of the matter.

### Response:
E is for energy, m is for mass, and c² is for the speed of light squared