Adi Shakti is the Power of Almighty God which is a single and integrated power. Although She exists as a complete and all-pervading power, She manifests through three separate powers. It is not possible however to completely separate the three powers of Adi Shakti from each other, because these powers belong to one personality, and are expressions of Her three moods (Gunas).
Additionally, it is a very difficult task to explain the manifestation of Her power which is far above human comprehension. Human beings have very limited weapons of perception (Ayudha) to understand Her. This can be explained by the analogy of a flute where the air passing through the instrument is a single current only, yet is capable of forming seven notes. In the same way, the one power of Adi Shakti is manifested in three forms while Her fourth integrated form is the source of the three powers. The power of Adi Shakti, the integrated complete form, is Pranava (Ruh, Anahalk, Rukh, Omkara or Holy Ghost). From this one can understand how OM (Pranava) is comprised of three separate forms ‘Aa’, ‘Oo’ and ‘Ma’.
These powers are:
1) The material power
2) The existence power
3) The sustenance power