# What is an Object?

Every object has a responsibility; finding the objects in a problem, and the job of each, is the first step in designing a program.

Novice · C# · OOP · Updated November 3, 2026

## After this lesson you can

- Identify the objects in a real-world system and the responsibility of each

## Key takeaways

- Every object has a responsibility: the job it's there to do.
- To find the objects in a problem, read its description. The nouns are often the objects, and the verbs are often their jobs.
- A good object has one clear job you can say in a sentence. When its job takes more than a sentence, it's often two objects.

Before writing any code, take a few minutes to list the **things** in your kitchen. For each one, ask: why do you have it? How do you use it? What is its job, its **responsibility**?

| Object | Its responsibility |
|---|---|
| Refrigerator | Keeps food cold |
| Dishwasher | Cleans dishes |
| Cupboard | Stores dishes and glasses |
| Plate | Holds food while you eat |
| Oven | Heats food to a set temperature |

Each object has a role, and no two objects have quite the same one. If you were to model a kitchen in software, you'd create virtual objects that do the same jobs they do in real life.

## Finding the objects in a problem

When you design a program, you do the same thing with the problem's description. The **nouns** are often the objects, and the **verbs** are often their jobs.

> A backyard basketball league has **teams**. Each team plays **games**, and the league keeps a **standings** table that ranks the teams by their winning percentage.

| Object | Its responsibility |
|---|---|
| Team | Knows its name and record; records wins and losses; works out its winning percentage |
| Game | Knows the two teams and the final score; says who won |
| Standings | Holds every team, and lists them in order |

## One clear job each

A good object has **one** clear responsibility, which you can say in a sentence. A refrigerator that also washed the dishes would be a strange appliance, and a `Team` that also printed web pages would be a strange object. When an object's job takes more than a sentence to describe, it's often two objects.

## Check yourself

1 question to try on the lesson page.

## So what

Designing with objects starts with words, not code: find the things in the problem, and give each one a single, clear job.

## Key terms

- [Object](https://www.ask-codey.com/glossary/object-oop)
- [Responsibility](https://www.ask-codey.com/glossary/responsibility)

## Cheat sheets

- [Working with Objects in C#: an overview](https://www.ask-codey.com/cheat-sheets/working-with-objects-in-csharp-an-overview-cheat-sheet)

Source: https://www.ask-codey.com/lessons/working-with-objects-in-csharp-what-is-an-object