为什么说snprintf比sprintf安全

#include <stdio.h>

int main()
{
	char buf1[6]={0};
	sprintf(buf1,"%s","hello world");
	printf("%s\n",buf1);//输出：hello world，所以sprintf不安全
	char buf2[6]={0};
	snprintf(buf2,sizeof(buf2),"%s","hello world");
	printf("%s\n",buf2);//输出：hello
	return 0;
}