MEAN is a “central value”.
If you multiply the mean by the number of data values in the dataset, you get the sum of all the data values.
MEDIAN is a “central value”.
If you order the data from least to greatest, the median is the data value in the middle, if there’s an odd number of data. When the number of data is even, split the data into two equal halves after ordering, and the median is the average of the highest value in the lower dataset and the lowest value in the higher dataset.
MODE is the most common value.
The mode is the data value that’s repeated most often. There may be more than one mode, or no mode at all. To qualify as a mode there must be more than one instance of a particular data value.
All three (mean, median, mode) are meant to represent the total dataset, or give a sense of its most meaningful value.