Can you explain the purpose and use of the keyword static in programming language?

In C#, the keyword static is used to declare class members (fields, methods, properties) that belong to the class itself rather than to any specific instance. This means such members exist in a single copy for the entire class and can be accessed without creating an object.

Application of static:

• Static fields store common data for all objects of the class.
• Static methods can be called directly via the class name.
• Static class — a class that contains only static members and cannot be instantiated.

Example:

public class Calculator
{
    public static int Counter = 0; // Shared among all objects

    public static int Add(int a, int b)
    {
        Counter++;
        return a + b;
    }
}

// Usage:
int result = Calculator.Add(3, 4);
Console.WriteLine(Calculator.Counter); // 1

Thus, static allows creating members shared among all instances and using methods without creating an object.