Yes, you can input multiple items from cin, using exactly the syntax you describe. The result is essentially identical to:
cin >> a;
cin >> b;
cin >> c;
This is due to a technique called "operator chaining".
Each call to operator>>(istream&, T) (where T is some arbitrary type) returns a reference to its first argument. So cin >> a returns cin, which can be used as (cin>>a)>>b and so forth.
Note that each call to operator>>(istream&, T) first consumes all whitespace characters, then as many characters as is required to satisfy the input operation, up to (but not including) the first next whitespace character, invalid character, or EOF.