how do pointers work

void MyFunct(char* buffer) {
    void* myvoid; // a pointer to void can point to anything
    char* b = new char[20];  // char array
    myvoid = b;  // memory address at myvoid is the same as at b
    strcpy((char*)myvoid, "this is text");  // memory address at myvoid is 't'
    std::cout << (char*)myvoid << '\n';  //print the string stored at myvoid
    buffer = NULL;  // set the buffer pointer to NULL
}

int main(int argc, char const *argv[]) {

    char* text = new char[20];  // initialise pointer to char of length 20
    if(text) {  // check if text is null
        std::cout << "wow text is initialised to null" << '\n';
    }
    MyFunct(text);
    if(text){  // null check
        std::cout << "text was null" << '\n';
    }
    std::cout << text << '\n';
    return 0;
}

/*
wow text is initialised to null
this is text
text was null

 */