Struct vs Record vs Class — Choosing the Right Type in Modern C# (.NET 9/10 Edition)

Struct vs Record vs Class — Choosing the Right Type in Modern C## (.NET 9/10 Edition) TL;DR In modern C#, developers have three primary ways to model data types : class struct record All three allow you to define custom types. But they behave very differently in terms of: • memory allocation • copying semantics • equality behavior • mutability • performance Choosing the wrong one can lead to: • unnecessary allocations • performance regressions • incorrect equality comparisons • subtle bugs in distributed systems In modern .NET architectures, understanding these differences is essential. This article breaks down exactly when to use each type , and why. The Core Difference: Value vs Reference Semantics Before we examine each type individually, we must understand the most fundamental distinction in .NET. Types fall into two categories: Value Types → stored directly → copied by value → typically allocated on the stack Reference Types → stored on the heap → copied by reference → multiple va