# C# glossary: Master level

31 C# terms at the Master level, each with a short definition and a link to its full page.

Updated: October 15, 2026

[Study these as flash cards](https://www.ask-codey.com/decks/c-sharp/master)

- [Assembly](https://www.ask-codey.com/glossary/assembly): A compiled .NET unit containing CIL, metadata, and sometimes resources.
- [Async/Await](https://www.ask-codey.com/glossary/async-await): Language features for pausing asynchronous work without blocking its thread.
- [Attribute](https://www.ask-codey.com/glossary/attribute-c-sharp): Metadata attached to C# declarations for compilers, tools, or runtime code.
- [Cancellation Token](https://www.ask-codey.com/glossary/cancellation-token): A value passed through operations to communicate a request for cancellation.
- [Common Intermediate Language (CIL)](https://www.ask-codey.com/glossary/common-intermediate-language-cil): Platform-independent instructions stored in .NET assemblies and executed by the CLR.
- [Common Type System](https://www.ask-codey.com/glossary/common-type-system): The .NET rules defining how types are declared, used, and shared across supported languages.
- [Deadlock](https://www.ask-codey.com/glossary/deadlock-c-sharp): A state where threads wait forever for locks held by one another.
- [Garbage Collection](https://www.ask-codey.com/glossary/garbage-collection-c-sharp): Automatic recovery of managed heap memory from objects a program can no longer reach.
- [Generational Garbage Collection](https://www.ask-codey.com/glossary/generational-garbage-collection): A strategy that groups objects by age so short-lived objects can be collected efficiently.
- [Heap Memory](https://www.ask-codey.com/glossary/heap-memory-c-sharp): Managed runtime memory where reference-type objects are generally allocated.
- [Lock Statement](https://www.ask-codey.com/glossary/lock-statement): A statement that allows only one thread at a time into a protected block for the same lock object.
- [Managed Code](https://www.ask-codey.com/glossary/managed-code): Code whose execution and memory are managed by the .NET runtime.
- [Memory Leak](https://www.ask-codey.com/glossary/memory-leak-c-sharp): Unwanted memory growth caused by retaining references to objects no longer needed.
- [Memory<T>](https://www.ask-codey.com/glossary/memory-t): A heap-safe representation of a continuous memory region that can survive asynchronous operations.
- [Metadata](https://www.ask-codey.com/glossary/metadata): Information stored in an assembly describing its types, members, references, and attributes.
- [Pointer](https://www.ask-codey.com/glossary/pointer): A variable containing the memory address of another value in unsafe code.
- [Race Condition](https://www.ask-codey.com/glossary/race-condition-c-sharp): A bug where a result depends on unpredictable timing between threads.
- [Record Type](https://www.ask-codey.com/glossary/record-type): A reference or value type designed for data with generated value-based equality.
- [ref Return](https://www.ask-codey.com/glossary/ref-return): Returning a reference to a storage location instead of copying its value.
- [ref struct](https://www.ask-codey.com/glossary/ref-struct): A value type restricted to the stack so it cannot outlive the memory it refers to.
- [Reflection](https://www.ask-codey.com/glossary/reflection-c-sharp): Inspecting and using types, members, and annotations at runtime.
- [Source Generator](https://www.ask-codey.com/glossary/source-generator): A compiler component that examines a program and adds generated C# source during compilation.
- [Span<T>](https://www.ask-codey.com/glossary/span-t): A stack-only view over a continuous region of memory without owning that memory.
- [Stack Memory](https://www.ask-codey.com/glossary/stack-memory-c-sharp): Per-thread memory commonly holding call frames, parameters, and local values.
- [Task](https://www.ask-codey.com/glossary/task): An object representing asynchronous work that may complete later.
- [Thread](https://www.ask-codey.com/glossary/thread-c-sharp): An independently scheduled path of execution inside a process.
- [Thread Pool](https://www.ask-codey.com/glossary/thread-pool): A runtime-managed group of reusable worker threads.
- [Unsafe Code](https://www.ask-codey.com/glossary/unsafe-code): A C# context that permits pointers and operations outside normal managed-memory safety.
- [ValueTask](https://www.ask-codey.com/glossary/valuetask): A value type representing asynchronous work that may already have a result.
- [Volatile Field](https://www.ask-codey.com/glossary/volatile-field): A field whose reads and writes receive special cross-thread visibility rules.
- [WebApplicationFactory](https://www.ask-codey.com/glossary/webapplicationfactory-in-tests): Starts an ASP.NET Core app in memory for tests.

- Previous level: [Freelancer](https://www.ask-codey.com/glossary/subjects/c-sharp/freelancer)

[Every C# term, by level](https://www.ask-codey.com/glossary/subjects/c-sharp)

Source: https://www.ask-codey.com/glossary/subjects/c-sharp/master