What is the meaning of the two parts specified between parentheses in a range-based for loop, separated by a colon? code example

Example: range based for loop c++

array<int, 5> values = {1, 2, 3, 4, 10};
// the type declaration below must be consistent with the array type
for (int x : values){ //we use a colon instead of in
cout << x << endl;
}