What is the fundamental difference between the brain mind and ego?

The Enlightened One explains: There are three divisions in our self:rnThe outer part is made up of:rnFive senses, rnMind (the gross mind where thoughts arise), rnThe physical body (the brain is part of it), rnSpeech. The inner part comprises of:rnMind (Mann, the subtle mind)rnIntellect (Buddhi)rnConsciousness (Chitt)rnEgo (Ahankar)rnBeyond that is the real Self, the Soul. Really speaking, we all are a Pure Soul. In any inner action that takes place in our self, the four components in the inner part together perform the inner action. Mind informs, Chitt visualizes, Intellect gives decision and Ego approves the decision. The operation of these four components is one kind of a parliamentary system. While mind and chitt are like voters who give their respective votes, the intellect, like a Prime Minister, gives decision, and ego is like the President who signs and approves the decision. When this inner action finishes, the outer action begins. Just as this body (of which brain is one of the components) is physical, the mind too is physical, and so is speech. The Soul is pure consciousness, whose function is to see and know the outer and inner actions. Let’s understand this through an example:rnSuppose we are in a seminar and we want to drink tea. rnFirst of all, a thought will come to our mind, ‘let’s have tea’. Mind is nothing but one giving thoughts, thoughts and thoughts; it’s a collection of thoughts only. Next, chitt will visualize where tea is available, how to reach there, this is one way and this is another. Chitt has the power of visualization. So it will show, ‘where is tea and how to get there.’ But until the intellect has not taken a decision, our body will not stand up and go there. Our intellect will check, ‘all are seated in a meeting, so we should not get up now.’ As soon as someone stands up and leaves the room, the intellect takes a decision, ‘It’s ok to get up now!’ The moment the intellect takes a decision, the ego signs it, ‘Yes, you can go.’ Once the ego signs that you may go, the physical body stands up, the speech comes out, “I’ll be back in five minutes.” and we go and have tea. This is how any action happens. rnWhen scientific circumstantial evidence occurs, automatically inner action takes place and outer action follows. The physical body will go to the place that the chitt has shown, will take tea and taste. At the time of tasting too, the moment the tea touches the tongue, the chitt will show, “Sugar is less. Where is sugar? Oh! It’s here.” So, mind will say, “I want more sugar.” The intellect will give the decision ‘take more sugar.’ The ego will sign it. The physical body will go there, add sugar, stir and drink tea. Even while drinking, the inner action continues. Chitt will show, the tea is sweet or not, hot or cold. Mind will show that tea is hot and comfortable. The intellect will compare, ‘This tea is good tea. It is better than that served in the hotel room.’ Thus, all this inner action is going on automatically within. Amidst all of this functioning that is happening automatically, we are not knowing our Pure SoulrnDue to ignorance of our real Self, we are believing that, ‘I am John (you may insert your name here).’ That is the subtlest level of egoism, which charges new karma. The mind, speech and body are all discharge karma. John entirely is discharge karma. Discharge karma means you have no control over John. You are not the doer of John. Thoughts are coming. You, as the Soul, are the knower. But since we do not know ‘who am I’, that’s why we believe, “I am thinking. I am speaking, I am doing (drinking tea, etc.).” That wrong belief of ‘I am the doer’ is called the subtlest egoism. That ego charges new karma. ‘I am John’ and ‘I am the doer’ are wrong beliefs. Due to these 2 wrong beliefs, karma is getting charged. And that charged karma automatically gets discharged in the next life. Just like suppose we sow a seed; after 3 months or 3 years, it will give fruits. Similarly mind, speech and body are fruits of past sown seed. To realize, really ‘who am I’ is called Self-RealizationrnWhen the Enlightened One enlightens our Soul, we realize, ‘I am really a Pure Soul’. The inner instrument of psyche (antahkaran) remains as it is even after one acquires Self-Realization.rnThe only thing that is destroyed is the wrong belief of one’s identity. When the Enlightened One gives us the right belief of ‘who am I’, the subtlest ego gets fractured, whereas the ego that remains in the inner psyche continues to conduct one’s remaining worldly activities, based on the discharge of karma, as and when it happens. To know more: https://www.dadabhagwan.org/path-to-happiness/spiritual-science/know-the-human-mind/