Scientific notation or exponents deals with the simplification of very large or small numbers into easy to read ones. Often used alot in sciences such as physics or in scientific math, scientific notation (referred to as exponents from here on in for naming conventions) can be used to describe the size of an electron, or the speed of light.
The speed of light in one such example is shown as:
3.0 x 10^8 or 3.0E8 Where 10^8 stands for 10 to the 8th exponent and 10E8 means the same.
The size of an electron could be described as this for an example:
3.45 x 10^-23 or 3.45E-23 Where 10^-23 means 10 to the -23 exponent (E the same), which is actually making it into a fraction, meaning that 3.45 x 10^-23 will be: