How can I find the CNF of ($A$ and $B$ or $C$) and ($B$ or not $C$) using a Karnaugh map?

Question

$$(A\land B \lor C) \land (B \lor \lnot C)$$

I know how to create the truth table and Karnaugh map of a logic expression. But I couldn't find exactly how to calculate the simplified CNF of it using the Karnaugh map.

I want to know, for CNF we have to use values $1$ or values $0$ in Karnaugh map?

Instead of an answer I want an explanation about it (a brief explanation about CNF would be great)