Mind & Self

AUM

AUM is a sacred syllable that is considered to be the greatest of all the mantra (sacred utterance). The syllable AUM is composed of the three sounds A-U-M (in Sanskrit, the vowels A and U coalesce to become O), which represent several universal triads. Thus, AUM mystically embodies the essence of the entire universe. It is uttered at the beginning and end of prayers, chants, and meditation.

AUM should not be pronounced as OM.

Buddhi

Buddhi is derived from the Vedic Sanskrit root Budh, which literally means "to wake, be awake, observe, heed, attend, learn, become aware of, to know, be conscious again".

Buddhi refers to our "wisdom mind" - the intellectual faculty and the power to "form and retain concepts, reason, discern, judge, comprehend & understand".

The purpose of Yoga is to train our Buddhi to help us make the right choice as it is our inner wisdom.

Manas

Manas refers to our "thinking mind" - the general thinking faculty, the conscious thinking via volition. It is the Manas that manifests intentions into thoughts, speech and actions.

The purpose of Yoga is to ensure that what we manifest in thought, speech & action are true & aligned with our true self.

Citta

The Citta refers to our "emotional mind" - your likes & dislikes, agitation & phobia etc. It is our Citta that reacts to emotional triggers.

Citta refers to our "fluctuating mind". An untrained Citta is why your attention jumps from one object to another. Without a specified object to focus on, the Citta is restless and unstable.

The purpose of Yoga is to tame this "monkey mind", and achieve a state of equanimity.

Ahamkara

Ahamkara is often translated as "ego" or "ego-consciousness", but it is actually more than that. It is the fabricated "false identity", consisting of personal pride, status in society, position at work etc.

And because of all these factors, you are enslaved to your "false-identity".

The purpose of Yoga is to dissolve this false sense of "self-identity".

Smrti

Smrti is a Sanskrit word, from the root Smara, which means "remembrance, reminiscence, thinking of or upon, calling to mind", or simply "memory".

Samskara

Samskara are the mental fabrications left by all thoughts, intentions and actions that an individual has ever experienced.

Samskara are thought patterns, and can be considered as psychological or emotional imprints that contribute to the formation of behavioral patterns. Samskaras are below the level of normal consciousness and are said to be the root of all impulses, character traits and innate dispositions.

Vasana

Vasana are the inherent tendencies developed from Samskara (impressions) from the present and past lifetimes that fuel the cycle of birth & death (Samsara) until they are exhausted.

It is believed that it is stored in our Hidden (Sub)conscious, which explains why we might like/dislike someone or something without any reason, or tend to know of something when we have not done it before, or know of places that we have not been there in this lifetime.

Klesa

Klesa are the afflictions of the mind, factors resulting in anguish, suffering and distress.

The 5 Klesa are:

Avidya (Delusion-Ignorance) is false knowledge, misunderstanding, or a lack of knowledge. Avidya is the first of the Klesha because it is the basis for the others. By destroying Avidya, the other Klesha are no longer an obstacle. Avidya obscures the higher Self by firmly establishing negative habits and preventing change.
Asmita (Egoism) is the attachment to ego and the ego's sense of reality. It is mistaking the physical, emotional and mental aspects of the mind-body for the true Self.
Raga (Attachment) is the desire (craving+attachment) for material objects, relationships, status, power or other unwholsome desires.
Dvesha (Repulsion) is aversion to unpleasant things, people and experiences. Manifestations include dislike, anger, wrath, rage & hatred.
Abhinivesa (Clinging To Life) is the fear of death and desire to live, even if life is filled with misery.

Pancha-Kosha

Kosha, often translated as "sheath", is a covering of the Atman, or "self" according to Vedantic philosophy.

The five sheaths (Pancha-Kosha) are described in the Taittiriya Upanishad (2.1-5), and they are often visualised as the layers of an onion:

Annamaya-Kosha: "Food" sheath -The physical body.
Pranamaya-Koshaa: "Energy" sheath - Prana, Shakti, Nadi, Chakra, Aura (Bio-electromagnetic field).
Manomaya-Kosha: "Mind" sheath - The thinking mind, emotions, likes & dislikes, agitation & phobia.
Vijnanamaya-Kosha: "Knowledge" sheath - Conscience, wisdom, discernment, intellect.
Anandamaya-Kosha: "Bliss" sheath - Pure consciousness/awareness, connection with the universe.

Traya-Sarira

The Pancha-Kosha are further classified as Traya-Sarira (Three Bodies):

Sthula-Sarira: The gross body, made up of physical matter, consists of Annamaya Kosha.
Suksma-Sarira: The astral body, consists of Pranamaya Kosha, Manomaya Kosha and Vijnanamaya Kosha.
Karana-Sarira: The causal body, consists of Ananadamaya Kosha.

Thus, the Pancha-Kosha/Traya-Sarira basically consistutes what we know as the "self".

Physical Form
Mental-Emotional Energies
Karmic Energies (The Hidden Consciousness, aka The Sub-consciousness)