a data structure is a collection of data and operations on said data, the data is represented as objects, and each object x has:
key(x): a key that is used to identify the object (usually a number that uniquely identifies the object)info(x)orvalue(x): contains the data needed to store for the object (usually without the key)
for example, if x is a person, key(x) could be the person's ID, value(x) would be information on said person, like age, height, weight etc..