Microsoft visual studio 2017 - getch() problem

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C++

C

#include
void main()
{
	printf("Hello C");
	getch();                          //Here getch() is used like this
}

#include
#include
void PrintMessage(void)
{
	printf("Hello C");
}

int main()
{
	PrintMessage();
	_getch();                        // here getchch() is used like this
}

I am executing it in Microsoft Visual studio 2017. Can you please explain to me this change that is required by the compiler in executing the command "getch()".

What I have tried:

Output is coming for both the programs. But since i am in beginners stage, i need to know about this change in one command.