No its not an approximation. It is transcendental, that is its not a

root of a polynomial with rational (or integer) coefficients.

Being transcendental it is irrational which means that it cannot be

writen as a ratio of integers, nor can it be written as a terminating

or periodic decimal.

see aboveWhy is pi only an approximation?

It has no meaning, but it is important in mathematics because itSecondly, what exactly is the meaning of the number e?

has interesting and usefull properties.

Specificaly it the the number which has the property that is the solution of:

satisfying .

see comments above aboutWhy is e only an approximation or is it?

RonL