It is very difficult, if not impossible to make any sort of inference based on a single data point. Psychology is the investigation of behavior that occurs regularly. Use Winnipeg murder frequencies for the last few years as a basis for talking about what can reasonably be stated based on a single number, or even a set of numbers. It's difficult to interpret what any one statistic is saying. But even inferential stats must be interpreted by someone who knows their language.
Descriptive statistics are the numbers that describe the phenomenon of interest.
Typically, they are simply measurements or counts. Descriptive stats are the basic data. Examples of descriptive stats are height, games won, stars given to movies, and annual income. Inferential statistics are more complex, because they are calculated using the descriptive statistics so that some conclusion can be inferred from the data. As you can see, inferential stats are technical and unusual while descriptive stats are common and typical.