Babar Ki Pehli Shaitaniya Yaad: Understanding 'Cognizance' Properly

I'm still trying to wrap my head around 'cognizance' in CrPC. All textbooks explain it as 'knowing or becoming aware' of a situation, but that doesn't really help. Can anyone tell me a concrete example from a real case, preferably from the IPC or any other notable case? For instance, what if someone files a fake complaint and the court still takes cognizance of it? Does that mean they're saying it's true or what? Someone clarify?