The "private" access specifier in C++ restricts access to class members, ensuring they can't be accessed or modified outside the class, thereby maintaining encapsulation and data integrity within the class.

Overloading refers to defining multiple functions with the same name but different signatures (usually different number or type of parameters). Overriding, on the other hand, is related to inheritance and polymorphism where a derived class provides a specific implementation for a method that is already provided by its base class. In overriding, the method in the derived class should have the same name, return type, and parameters as the method in the base class. The key difference is thus related to polymorphism and inheritance for overriding versus method signature differences for overloading.

For a recursive function to successfully terminate, it must have a base case. A base case is a condition under which the function stops calling itself and starts returning values. Without a base case, a recursive function would call itself indefinitely, leading to an infinite loop and, in most cases, a stack overflow error.

The C++ STL provides a plethora of algorithms for various operations, but "magic_square" is not among them. binary_search, find, and sort are standard algorithms provided in the STL.

The International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) jointly maintain the C++ language standard. Specifically, the ISO/IEC JTC1/SC22/WG21 committee is in charge of the C++ standard's evolution.

Function overloading allows multiple functions in the same scope to have the same name as long as they have different parameter lists. In C++, the appropriate overloaded function is chosen at compile-time based on the function call's arguments.

The keyword virtual is used in C++ to make a function virtual. When a function is declared as virtual, it can be overridden in any derived class. This allows for dynamic polymorphism, where the decision on which method version to execute is made at runtime based on the object's actual type.

The if-else control structure in C++ provides a way to perform decision-making operations. If the condition inside the 'if' block evaluates to true, the 'if' block of code is executed; otherwise, the 'else' block is executed, if present. It can be used to check multiple conditions in sequence by nesting or using "else if".

shared_ptr uses reference counting, which means it keeps a count of the number of shared_ptr objects referring to the same memory location. When this count drops to zero (meaning no shared pointers are referring to the object), the memory is automatically deallocated.

In C++, there isn't a direct concept of "interfaces" as in some other languages. However, abstract classes with only pure virtual functions can act similarly to interfaces. These ensure abstraction by forcing derived classes to provide concrete implementations, but not all abstractions need to be interfaces.