A dataset is a collection of data, often in tabular or matrix form. This tag is NOT intended for data requests ("where can I find a dataset about ...") --> see OpenData
Most commonly a dataset corresponds to the contents of a single database table, or a single statistical data matrix, where every column of the table represents a particular variable, and each row corresponds to a given member of the dataset in question. The dataset lists values for each of the variables, such as height and weight of an object, for each member of the dataset. Each value is known as a datum or data point.
The term dataset may also be used more loosely, to refer to the data in a collection of closely related tables.