The mind has 4 components :

1. “MANAS” is the Cogitative aspect of the human mind . It keeps modifying and thinking considering pros and cons of everything. Normal thinking .

 Sanskrit definition : "sankalp vikalpatmika antahkarna vritti"

2. “Buddhi” is specialized way of thinking and is the determinative aspect of the human mind i.e. It is the mind which has come to decision , the determinative aspect .

Sanskrit definition : "nishchayatmika antah karna vritti" . 

3. “Chitta” is a memory bank. Mind is loaded with lot memories which is called the chitta aspect of the human mind . i.e. It means it is a memory bank loaded with all experience of past , some of it has come out and some are yet there as memory . MOST of the HUMAN thoughts are memory ( Chitta)

Sanskrit definition : "Anusandhanatmika antah karna vritti"

4. “Ahankar” It is the self referential aspect of the human Mind . We could call it ego or I i.e. MIND Functions through these 4 Functional Aspects of mind

Sanskrit definition : "Ahamatmika antah karna vritti "