Descriptive statistics is the branch of statistics that aims to provide a summary of a given data set, allowing observers to gain key insights into a large set of data without having to spend hours focused on individual pieces of information. It allows researchers to measure and characterize the central tendency of a data set, identify the spread and variance of the data points, and produce a detailed description of the distribution of the information. In other words, it provides an overall picture of the data and brings out its essential features.

Measures of central tendency are the most common tools used in descriptive statistics. This involves the calculation of important measures such as the mean, median and mode in order to provide an overall picture of a set of data. The mean, which is the average of all values in the data set, is most commonly used and is accepted as a reliable measure for central tendency in a normal distribution. A median, on the other hand, is a more accurate measure for central tendency when dealing with data points that are not normally distributed. Lastly, the mode is the value that appears most often in a set of data and is usually the most widely recognized measure of central tendency.

Descriptive statistics also involve the calculation of variance and standard deviation, which are two measures of variability. Variance gives a numeric indication of how far each data point is from the mean of the data set, while the standard deviation quantifies the amount of variation in any given set of numbers. The standard deviation is useful in helping to identify any outliers that may not have been obvious at first glance.

The last form of descriptive statistics has to do with frequency distributions. A frequency distribution table is a systematic way of displaying and counting the occurrences of each of the values in a set of data. Frequency distributions allow researchers to gain an understanding of how the values in a given data set are distributed in relation to one another. This is important in order to assess the range and type of data points present in a given set.

Descriptive statistics provide researchers and analysts with an understanding of the properties of a given data set. A good understanding of the fundamental ideas behind descriptive statistics is important in order to effectively utilize and understand the analytics that come out of this field. Analysing a data set using descriptive statistics allows researchers to understand the big picture with respect to the information they have and can be used as an essential tool in decision making processes.