Structs are a language feature.
A composite data type (or record) declaration that defines a physically grouped list of variables to be placed under one name in a block of memory, allowing the different variables to be accessed via a single pointer.
Languages with Structs include C, Ion
struct account {
int account_number;
char *first_name;
char *last_name;
float balance;
};
{ first : "Tom" , last: "Riddle" } // Structure with two fields
{"first":"Tom","last":"Riddle"} // The same value with confusing style
{center:{x:1.0, y:12.5}, radius:3} // Nested struct