Move modules define struct definitions. Struct definitions may include the abilities such as key or store. Resources are struct instance with The key ability that are stored in global storage or directly in an account.

The store ability allows struct instances to be stored within resources. An example here is how the APT coin is stored: CoinStore is the resource that contains the APT coin, while the Coin itself is an instance:

/// A holder of a specific coin type and associated event handles.
/// These are kept in a single resource to ensure locality of data.
struct CoinStore<phantom CoinType> has key {
coin: Coin<CoinType>,
/// Main structure representing a coin/token in an account's custody.
struct Coin<phantom CoinType> has store {
/// Amount of coin this address has.
value: u64,