Used LINQ? What is materialization?

LINQ (Language Integrated Query) is a technology in C# that allows writing data collection queries in a unified syntax integrated into the language. It simplifies working with data, making the code more readable and declarative.

Materialization in the context of LINQ is the process of executing the query and transforming its result from a deferred (lazy) representation into a concrete collection or object in memory. For example, when you call methods like ToList(), ToArray(), First(), materialization occurs — the query is executed, and data is loaded.

Example:

var numbers = new List<int> {1, 2, 3, 4, 5};

// LINQ query (deferred)
var query = numbers.Where(n => n > 2);

// The query has not been executed yet

// Materialization
var result = query.ToList(); // The query is executed, and the result is loaded into a list

Without materialization, LINQ queries to data sources (e.g., to a database via Entity Framework) are not executed, which allows optimizing data operations.