MCA eligibility is university-specific. A bachelor's degree is normally required, while mathematics or a computing background can be an additional condition for some programmes. For an MCA learner, the best way to understand MCA without BCA is to connect the theory with a small working example. This point is specifically relevant to the MCA without BCA aspect of MCA study. For this specific question about MCA without BCA, the practical takeaway is to relate the concept to your own MCA learning goal.