In C#, a method declared
async won't block within a synchronous process, in case of you're using I/O based operations (e.g. web access, working with files, ...). The result of such async marked methods may be awaited via the use of the
When you use the yield keyword in a statement, you indicate that the method, operator, or get accessor in which it appears is an iterator. Using yield to define an iterator removes the need for an explicit extra class (the class that holds the state for an enumeration) when you implement the IEnumerable and IEnumerator pattern for a custom collection type.
An event is a notification that something has occurred (such as a mouse click) or, in some cases, is about to occur (such as a price change).
Classes can define events and their instances (objects) may raise these events. For instance, a Button may contain a Click event that gets raised when a user has clicked it.
Event handlers are then methods that get called when their corresponding event is raised. A form may contain a Clicked event handler for every Button it contains, for instance.
LINQ is an acronym which stands for Language INtegrated Query. It is a concept which integrates a query language by offering a consistent model for working with data across various kinds of data sources and formats; you use the same basic coding patterns to query and transform data in XML documents, SQL databases, ADO.NET Datasets, .NET collections, and any other format for which a LINQ provider is available.