Structs are a carry-over from the C; in C++, classes are generally used. In C++, they're essentially the same as classes, except structs' default access modifier is public.
Class example:
class Point {
public:
double x;
double y;
};
Struct example:
struct Point {
double x;
double y;
};
In C++ struct and class can be used interchangeably to create a class with one exception: