What the relationship between descriptive and inferential statistics?
Descriptive statistics includes description of given sample data, without making judgement about population. For example: sample mean can be calculated from sample, and it is a descriptive statistic.
Inferential statistics derive a conclusion about population on the basis of sample. For example, inferring that majority of people support one candidate (on the basis of a given sample).
Relationship: Since we don't have access to entire population, we use descriptive statistics to make inferential conclusions.