Deeksha is originally a yogic initiation and is a well recognized approach for activating the Kundalini, your inherent life force potential. A being with an awakened Kundalini, a Siddha (one who has accomplished and completed the path of kundalini within themselves) acts as a channel for the transmission of the cosmic spiritual energy into the aspirant, initiating their own inherent flow of Kundalini. Deeksha activates, awakens and guides the ascent of the Kundalini energy, depending on the type of initiation that occurs:

Pranapat (Anvi Deeksha)

This initiation involves infusing an individual with large amounts of Prana (vital life force) through the initiator. The prana then floods the subtle energetic system, it irrigates the naadis & meridians, unblocking the pathway for Kundalini. Rise of Prana through the subltle system is a precursor to awakening of kundalini.

The prana moving through the peripheral energy channels might aswell generate sensations, phenomenon, experiences, Kriyas and states of trance which resemble samadhi, though it should not be mistaken for awakening of kundalini. Although these are clearings of a lower order, the energy and the spontaneous movement of kriyas in case of stirring and rise of prana (Pranotthan) is raw unfocused, unscattered, misaligned and not in synergy as compared to kriyas caused by kundalini awakening.

This type of transmission only enables higher levels of initiation to take place eventually. This pranic activity does not enable Samadhi (meditative absorption) or Enlightenment and so is of a lesser depth and degree.

Shaktipat (Shaktipat Deeksha)

The Siddha not only transfers prana in this type of initiation, but also directs it to enter the primary columns of energy in the spine, ida pingala & sushumna, and the energy begins to work on clearing the accumulated karmic impressions and blockages of the deepest level.

The Guru may also trigger Kundalini and assist its ascension up the main channels instead of it entering the peripheral meridians. The transmission can also further help dissolve karma and accumulated impression, which are absorbed by the initiating Guru.
The Kriyas (spontaneous automatic movements and expressions) are more advanced and refined as compared to random jerks and shakings, they are more complex yogic asanas, bandhas, mudras and pranayams as well as glimpses of Samadhi and states of immersion in awareness-consciousness-bliss.

This inspires and propels the process of clearing even further. It is only after the ascent of Kundalini and its path completion that spontaneous meditation happens and not before it.

Shivapat (Shambhavi Deeksha)

This is the highest and rarest of all orders of initiation and is not in essence a transfer of energy but more of an attunement due to sympathetic resonance. The Siddha is capable of bringing the initiate into their natural stateless state of non conceptual, non dual awareness through acclimation to their own state of beingness.

Since you are already that non dual stateless state, beingness, awareness, it cannot be transmitted to you. No one can give you what you already are.Shivapat effortlessly attunes you to the state of Samadhi. There is cesation of all movement, kriyas, sensations, experience and phenomenon, as well as the perceiver of it all. The mind dissolves in the almost tangible stillness/emptiness and one merges with the self effulgent awareness prior to that stillness.

The flux of Shakti (Kundalini) is thus made to stabilize as it is integrated and anchored into the beingness. This is a glimpse of Enlightenment – a merging of the two aspects of Kundalini, Shiva (pure being, nothingness, the unmanifest) and Shakti (dynamic creative potential, the manifest/created). This is the absolute stage and aim of the kundalini process.