The Sanskrit word Shakta represents the name given to those who worship the Mother Goddess or Divine Shakti. The form which this worship may take varies greatly between diverse traditions and individuals.

In a manner of speaking, Shaktas are often categorized as Dual, Non-Dual and Mixed.

This can be explained as those who worship Shakti in the form of an image or idol (Dual); as those who worship Shakti as a radiant consciousness without distinction to inner or outer (Non-Dual); and as those who worship in both manners (Mixed).

A further definition of Shakta, though more arcane is the idea that a Shakta is a “holder of Shakti”. This is to say, a Shakta has or is able to express the Divine Shakti through their own individual being.

Recommended reading
The Star Path by Shri Gurudev Mahendranath.