Normal Distribution or Gaussian Distribution:
The normal distribution is considered the most prominent probability distribution in statistics. There are several reasons for this:
1) The normal distribution is very tractable analytically, that is, a large number of results involving this distribution can be derived in explicit form.
2) The normal distribution arises as the outcome of the central limit theorem, which states that under mild conditions the sum of a large number of random variables is distributed approximately normally. Finally, the “bell” shape of the normal distribution makes it a convenient choice for modelling a large variety of random variables encountered in practice.
For this reason, the normal distribution is commonly encountered in practice, and is used throughout statistics
The probability density function (pdf) of a random variable describes the relative frequencies of different values for that random variable.
The pdf of the normal distribution is explained in detail in the attached sheet