.data( key, value )

Store arbitrary data associated with the matched elements or return the value at the named data store for the all elements in the set of matched elements.

    $(selector).data("key",value)

.data( key )

Return selected data store of the first element in the set of matched elements.

    $(selector).data("key")

.data()

Return all the data stores of the first element in the set of matched elements.

    $(selector).data()