Interface classes

The interface classes are more like a template of a class. The interface show how must be the subclass, which methods must implements, those methods must not be implemented here but in the subclasses Those classes are used to organize a serie of future classes which will act all together. It is like the guidelines all the subclasses must follow. Here is an example:

public interface CompanyInterface{
public void buySupplies();
public void paySalaries();
}
public class Supermarket implements CompanyInterface{
public void buySupplies(){
System.out.println("Buying fruits...");
}
pubilc void paySalaries(){
System.out.println("Paying cashiers...");
}
}
public class Garage implements CompanyInterface{
public void buySupplies(){
System.out.println("Buying tyres...");
}
pubilc void paySalaries(){
System.out.println("Paying mechanics...");
}
}