A conception is a self impression or idealisation of an object or situation, that is, it depends on the person who perceiving the event and as such it depends on the person culture, religion, morals, superstitions, etc. A concept in the other hand is a well defined precept or phenomena and does not depend on the perception of individuals Best Regards, Al

A "concept ' is the idea itself or the notion ,the 'conception ' is the perception of the idea. They could be interchangeable still ,when in reference to meanings or ideas , it depends on the context. They are both mental abstract symbols of an idea ! The concept of an idea could refer to the intuitive notion of it or it could be the idea formed by constructive combination of all its aspects and regards. The conception of an idea is how your mind perceives it and defines it , how it understands and recognizes its characteristics So in fact you they can replace each other in a context ,but will have slight difference in reference to the idea mentioned !

A concept is an idea. This is a countable noun. 'A concept' is a single idea, 'concepts' are ideas. 'Conception' has two meanings. It can mean the beginning of something. It can also mean the mental capacity to grasp an idea, as in 'I have no conception of ...'. This is an uncountable noun.