pls explain e=mc² in the simplest way. thanks!?

This equation says that the potential energy contained in matter is the mass of the matter times the speed of light (c) squared.

If you work this out for just a kilogram of matter, it's an incredible amount of energy. That's why just a few dozen kilos of fissionable material (uranium or plutonium) in an atomic bomb are so destructive.

The units work out thus:
Energy = kg · (m/sec)² = kg·m²/sec²
= kg·m·m/sec²
= kg·m·Acceleration (distance over time square is acceleration)
= kg·Force (acceleration applied thru a distance is force)
= Energy (force applied to a mass is energy)

This is more of a physics question but,

It is a measure of the amount of energy (e) is equal to any given mass at rest (m) multipled by the speed of light (c) squared

Einstein is given credit, but it is based on the Maxwell's equations regarding electromagnetism. Electromagnetic fields travel at the speed of light in a vacuum.

There is a heck of a lot on the subject, this is just a very general answer.

You can read and try to understand how Einstein discovered this equation, but you will get a nosebleed. Much easier if you follow Maxwell, Faraday and Lenz.

This is an equation.
E is energy.
MC^, M is mass C is the speed of light squared.
An interesting thing about this equation,if you give it a time factor,for instance.
Hold a marble in your hand for say 20 years and have it turn into energy it would probably stay hot while it's mass became energy.
If it was turned into energy in,say one one-thousands of a second it would do major damage to the surface of the earth.

energy is equal to the product of mass and velocity of light

e=mc^2 means that energy can be converted to matter and vice versa.