Hypothesis testing is used to determine if an assumption about a set of data is true. Ideally, you would conduct statistical analysis on the entire population. Since this is near impossible, a random sample data set of the population is examined against an assumption.
There are two types of hypothesis:
Null Hypothesis (Ho)
Alternate Hypothesis (Ha)
Ho assumes that there is no difference in the hypothesis while Ha states that there is a difference or relationship in the hypothesis.