A null hypothesis is a statistical hypothesis that states that no distinction exists between certain features of a population (or data generating process). A gambler, for example, may be curious about the fairness of a game of chance
In other words, a null hypothesis is opposite to the alternative hypothesis in any research setting. Whereby an alternative hypothesis is a declarative statement about certain or uncertain relationships between two or more variables.
The variables are the ones changing value or having the capacity to have to change value.
The Null Hypothesis is, therefore, the “not” side of the said expected relationship of the alternative hypothesis.