Stage 1 - C# and .NET Basics

Q1. What is C#?

Quick interview answer: C# is a programming language from Microsoft. It is used to build backend applications, Web APIs, desktop apps, cloud apps, and enterprise software. In .NET jobs, C# is commonly used with ASP.NET Core, SQL Server, Entity Framework Core, and Azure.

Study in detail: What is C#? - This article expands the topic with complete explanation, examples, and practice code.

Q2. What is the difference between C# and .NET?

Quick interview answer: C# is the language we write. .NET is the platform that runs the C# program and provides the runtime, libraries, SDK, and project templates. So C# is like English, and .NET is like the environment where that English is understood and executed.

C#   = language
.NET = platform that runs C# applications

Study in detail: C# Introduction - This article expands the topic with complete explanation, examples, and practice code.

Q3. Why do backend developers use C#?

Quick interview answer: Backend developers use C# because it is strong for APIs, business logic, database applications, and cloud systems. It is type-safe, mature, fast, and widely used in companies that build enterprise applications.

Study in detail: Why C# for backend? - This article expands the topic with complete explanation, examples, and practice code.

Q4. What software do we need to write C# programs?

Quick interview answer: To write and run C# programs, we need the .NET SDK, a code editor, and a terminal. The SDK gives us commands like dotnet new, dotnet build, and dotnet run.

Study in detail: C# Setup - This article expands the topic with complete explanation, examples, and practice code.

Q5. What is Program.cs?

Quick interview answer: Program.cs is usually the starting file of a C# console application. For beginners, it is the first place to write code and see output using Console.WriteLine.

Study in detail: Program.cs and setup - This article expands the topic with complete explanation, examples, and practice code.