Understanding Spring Field Injection

package com.studytonight.community;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class App {

    public static void main(String[] args) {
        
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(AppConfig.class);
        Writer writer = context.getBean("fictionWriter", Writer.class);
        writer.write();
        writer.getAward();
        // Close the context
        context.close();
    }
}

package com.studytonight.community;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

@Configuration
@ComponentScan("com.studytonight.community")
public class AppConfig {

}

package com.studytonight.community;

import org.springframework.stereotype.Component;

@Component
public class Award {
    
    public void award() {
        
        System.out.println("Your Writting got Award!");
    }
}

package com.studytonight.community;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

@Component
public class FictionWriter implements Writer {

    @Autowired
    Award award;

    @Override
    public void write() {
        
        System.out.println("Write Fiction Novels...");
    }

    @Override
    public void getAward() {
        
        award.award();
    }
    
    
}

package com.studytonight.community;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

@Component
public class TechnicalWriter implements Writer{

    @Autowired
    private Award award;

    @Override
    public void write() {
        
        System.out.println("Write technical stuffs...");
    }

    @Override
    public void getAward() {
        award.award();
        
    }
}

package com.studytonight.community;

public interface Writer {
    
    void write();
    void getAward();
}

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.studytonight</groupId>
  <artifactId>springproject</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <dependencies>
  <!-- https://mvnrepository.com/artifact/org.springframework/spring-web -->
  <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>
    </dependencies>
    <properties>
        <spring.version>5.2.8.RELEASE</spring.version>
    </properties>
  <build>
    <sourceDirectory>src</sourceDirectory>
    <plugins>
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.8.1</version>
        <configuration>
          <source>1.8</source>
          <target>1.8</target>
        </configuration>
      </plugin>
    </plugins>
    
  </build>
</project>