Most people would say that what math you learn in school is useless in the real world. That all algebra and geometry is just a waste of time. However, math is the most used concept in the world. Computers, science, etc. all need some mathematical equation to make it possible. e has changed how society looks on banking. e has changed how we compute continuous compound interest. Although people say e is not as important as a mathematical computation such as pi, we use e a lot and its history is just as interesting as any mathematical component.
e is a component in mathematics. John Napier discovered e in 1618, although he did not recognize it. Napier was working on logarithm appendix, where the natural logarithms of various numbers appeared on a table where e was initially discovered. In 1624, Briggs almost discovered e and gave the numerical approximation to the base 10 logarithm of e but did not mention e in his work. In 1661, Huygens got the relationship between rectangular hyperbola and the logarithm. He also defined a curve, a "logarithmic" curve, but we call it the exponential curve, the equation is y=ka^x. Huygens also calculated the base of e to 17 decimal places, but e still remains undiscovered.
e was finally discovered in 1683 when Jacob Bernoulli was doing a study on compound interest. He looked at the problem, examined continuous compound interest, and tried to solve the limit of (1+1/n)^n because n tends to infinity. He used the binomial theorem and discovered that this limit had to be between 2 and 3. However, he did not make any connection between his work and logarithms and he did not directly call e e.
In 1690, Leibniz wrote a letter to Huygens and used the notation b for e. e was finally recognized. Euler made many accomplishments to the discovery of e that first called e e. He also figured that e=1 +1/1! +1/2! +1/3! + and e is the limit of (1+1/n)^n as n tends to infinity.