What is the difference between a field and a property?

A field is a variable stored in a class. A property wraps access to data with get and set accessors, letting you add validation or restrict who can change a value.

When should I use a record instead of a class?

Use a record for data-focused types where value equality and immutability make sense, such as coordinates or API response models. Use a class for types with identity and changing state.

C# Classes, Properties, and Records

Introduction

C# is an object-oriented language: you describe things as types and create objects from them. This tutorial builds a small Person class using properties and a constructor, then shows how records give you a shorter way to define simple data types.

Prerequisites

The .NET SDK installed
Basic C# syntax: variables, methods, and string interpolation

Step-by-Step Guide

Step 1: Define a class with properties

Properties expose data through get and set accessors. Using a private setter means only the class itself can change the value.

public class Person
{
    public string Name { get; set; }
    public int Age { get; private set; }
}

Step 2: Add a constructor and methods

A constructor has the same name as the class and sets up the initial state. Expression-bodied members (=>) keep short methods compact.

public class Person
{
    public string Name { get; set; }
    public int Age { get; private set; }

    public Person(string name, int age)
    {
        Name = name;
        Age = age;
    }

    public void HaveBirthday() => Age++;

    public string Describe() => $"{Name} is {Age} years old.";
}

Step 3: Create and use objects

Use new to create an instance and call its methods.

var ava = new Person("Ava", 30);
ava.HaveBirthday();
Console.WriteLine(ava.Describe());   // Ava is 31 years old.

Step 4: Use records for simple data

A record is a concise type for immutable data. Records compare by value, so two records with the same values are equal.

public record Point(int X, int Y);

var a = new Point(1, 2);
var b = new Point(1, 2);
Console.WriteLine(a == b);   // True

FAQs

What is the difference between a field and a property?: A field is a variable stored in a class. A property wraps access to data with get and set accessors, letting you add validation or restrict who can change a value.
When should I use a record instead of a class?: Use a record for data-focused types where value equality and immutability make sense, such as coordinates or API response models. Use a class for types with identity and changing state.

Summary

Classes bundle data and behavior, properties control access, and records give you compact, value-based types. Together they cover most everyday modeling needs in C#.