Doubt in Company Law - Memorandum and Articles of Association

Yaar samajh nahi aaya, I'm stuck. In Chapter II of the Companies Act, it's written that every public company has to have a Memorandum of Association (MoA) and Articles of Association (AoA). But what's the difference, please help? Both are kinda like the company's constitution, na? MoA is supposed to contain all the main objectives, powers, and scope of the company, but then AoA is like, what the company rules are, right? And AoA can even override MoA in certain cases, kya? I'm getting confused here. In the case of Shree Ram v. Union of India, the Supreme Court said that AoA can't be in conflict with the MoA. But what about when AoA says something that's not in the MoA? Is it still valid?