What is the difference between an error and an exception?

Error represents an unrecoverable problem that occurs outside the control of the application. It is usually related to JVM resources (for example, stack overflow or out of memory). The application cannot recover from such a problem.

Exception represents a problem that can potentially be handled by the application. It occurs during program execution and can be caused by various reasons, such as incorrect user data, loss of network connection, or an attempt to access a non-existent file.

Main differences:

Characteristic	Error	Exception
Recoverability	Unrecoverable problem	Potentially recoverable problem
Control	Outside the control of the application	Can be handled by the application
Inheritance	Inherits from java.lang.Error	Inherits from java.lang.Exception
Handling	Usually not caught explicitly (unchecked)	Can be caught and handled (checked/unchecked)

Examples:

// Error example
public class StackOverflow {
    public static void recursiveMethod() {
        recursiveMethod(); // Infinite recursion causes StackOverflowError
    }

    public static void main(String[] args) {
        recursiveMethod();
    }
}

// Exception example
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;

public class FileRead {
    public static void main(String[] args) {
        try {
            File file = new File("nonexistent_file.txt");
            Scanner scanner = new Scanner(file);
            while (scanner.hasNextLine()) {
                System.out.println(scanner.nextLine());
            }
            scanner.close();
        } catch (FileNotFoundException e) {
            System.err.println("File not found: " + e.getMessage()); // Exception handling
        }
    }
}