Difference between data assignment in pointer and a variable

Question

Why does the program exit with exception when i use the array variant instead of the pointer.

int main()
{

  //  unsigned char data[1920 * 1080 * 4];   this causes the  exception

    unsigned char* data = new unsigned char[1920 * 1080 * 4];

    std::cout << "Hello World!\n";
}

Answer 1

Automatic storage duration (the commented case) has a limit of about 1Mb on current platforms.

Dynamic storage duration (the uncommented case) allows for much larger contiguous blocks to be allocated. (In excess of 1Gb on current platforms).

The C++ standard doesn't mandate specific limits.