C++ Introduction: What It Is and Why Learn It

C++ (pronounced "C plus plus") is a fast, compiled, general-purpose programming language. It gives you two things that rarely come together: high-level features such as classes, templates and a rich standard library, and low-level control over memory and hardware. That combination is why C++ runs inside web browsers, game engines, databases, operating systems, trading platforms and the firmware of everyday devices.

This is the first lesson of the MakeMyCodes C++ tutorial. It explains what C++ is, where it came from, why it is still one of the most important languages, and what happens when you turn C++ source code into a running program. The next lessons cover installing a compiler, syntax, variables and data types, with every program actually compiled and run.

Think of programming languages as vehicles. Python is an automatic car: easy to drive, and it takes care of most things for you. C++ is a manual sports car: you control the gears yourself, which takes practice, but you get the maximum performance out of the engine.

What is C++?

In one sentence: C++ is a statically typed, compiled language that supports procedural, object-oriented and generic programming, and gives the programmer direct control over memory. Let's break that down:

A short history of C++

C++ was created by Bjarne Stroustrup at Bell Labs, starting in 1979. He wanted the speed and hardware access of the C language together with the classes of Simula, a language that made large programs easier to organise. His first version was literally called "C with Classes". In 1983 it was renamed C++: in C, ++ is the increment operator, so the name means "one step beyond C".

Since 1998 C++ has been an ISO international standard, and a new version now appears every three years:

The compiler tells you which standard it is using through the predefined value __cplusplus. We compiled one tiny program with GCC's g++ 14.2 under different -std options:

-std=c++11  __cplusplus = 201103
-std=c++14  __cplusplus = 201402
-std=c++17  __cplusplus = 201703
-std=c++20  __cplusplus = 202002
-std=c++23  __cplusplus = 202302

Without any option, g++ 14 used 201703, that is, C++17. In this tutorial we compile with -std=c++20.

Why learn C++ today?

• Performance: C++ compiles to native machine code with no garbage collector pausing your program. When every millisecond or every megabyte matters, C++ is usually the first choice.
• Control: you decide how memory is used. That's essential for games, embedded devices with a few kilobytes of RAM, and real-time systems.
• It's everywhere: much of the software you use daily is written in C++, so the jobs and the existing code bases are huge.
• It teaches you how computers work: memory, the stack and heap, pointers, compilation and linking. That knowledge makes you better in every other language, including C#, Java and Python.
• Strong in interviews and competitive programming: the STL (vectors, maps, algorithms) and C++'s speed make it the most popular language on competitive-programming platforms.

Where C++ is used

Key features of C++

• Object-oriented programming: classes, objects, encapsulation, inheritance and polymorphism (covered later in this course).
• Templates: write one function or class that works with many types; the STL is built on them.
• Standard Library: ready-made strings, dynamic arrays (std::vector), maps, algorithms, input/output, threads and more.
• Manual and automatic memory management: you can allocate memory yourself, but modern C++ prefers RAII and smart pointers, which release resources automatically.
• Compatibility with C: most C code can be used directly from C++, giving access to decades of libraries.
• Portability: standard C++ code compiles on Windows, Linux, macOS and embedded platforms. The source is portable; the compiled executable is built separately for each platform.
• Case sensitive: total, Total and TOTAL are three different names.

How a C++ program becomes a running program

This is the most important difference from languages like Python. A C++ source file goes through four stages before it can run:

hello.cpp  --(1) preprocessor-->  expanded source  --(2) compiler-->  assembly
          --(3) assembler-->  hello.o (object file)  --(4) linker-->  hello / hello.exe

1. Preprocessing: lines starting with # are handled first. #include <iostream> literally pastes the contents of the iostream header into your file. Our 7-line hello-world program grew to 33,392 lines after preprocessing (g++ -E hello.cpp).
2. Compilation: the compiler checks syntax and types, optimises, and translates C++ into assembly code for your processor.
3. Assembly: the assembler turns that into machine code in an object file (.o or .obj). Ours was 2,272 bytes.
4. Linking: the linker combines your object files with the libraries you use (here, the C++ standard library) and produces the final executable. Ours was 18,832 bytes.

Usually one command does all four steps: g++ hello.cpp -o hello. Knowing the stages helps you understand error messages: a compiler error means your code is wrong (a missing semicolon, an unknown name), while a linker error ("undefined reference") means something was declared but its implementation couldn't be found.

Here is the classic first program and its real output. The syntax lesson explains every line.

#include <iostream>

int main()
{
    std::cout << "Hello, World!" << std::endl;
    std::cout << "Welcome to C++ at MakeMyCodes" << std::endl;
    return 0;
}

Hello, World!
Welcome to C++ at MakeMyCodes

C vs C++ vs Java vs C#

If you already know C#, much of the syntax will look familiar, because C# borrowed it from C and C++. The big new ideas will be header files, pointers, manual memory control and the compile-and-link model.

Advantages and disadvantages

Interview questions

Who developed C++ and why is it called C++?

Bjarne Stroustrup at Bell Labs, starting in 1979, as "C with Classes". It was renamed C++ in 1983; ++ is C's increment operator, meaning an improved C.

Is C++ a purely object-oriented language?

No. C++ supports object-oriented programming, but you can also write procedural code with free functions and global variables, and generic code with templates. Every program starts in the free function main(), not inside a class.

Is C++ compiled or interpreted?

Compiled. The compiler and linker produce a native executable for a specific platform, which runs directly on the processor without an interpreter or virtual machine.

More questions are on the C++ basics interview questions page.

Summary

• C++ is a compiled, statically typed, multi-paradigm language created by Bjarne Stroustrup as an extension of C.
• It combines high-level features (classes, templates, the STL) with low-level control over memory.
• It's used where performance matters: games, browsers, databases, finance, embedded systems and the core of ML libraries.
• Source code goes through preprocessing, compilation, assembly and linking to become an executable.
• A new ISO standard appears every three years; "modern C++" means C++11 and later.

Next lesson: Install a C++ compiler on Windows and run your first program.