Thread: Don't know java ...Need help compare, explain 2 different versiosn of code.

I don't know anyting aboutjava programing. Please explain to me whatcodes below mean?Differences between 2 version?
Thanks for all the help that one can provide. Truly ppreciated.

Taskmanager.java

Version 2.0
public interface TaskManager {
Task[] getTasks();
public Task getRootTask();
public void clear();
public GanttTask getTask(int taskId);
public void registerTask(Task task);
public GanttTask createTask();

version 2.1
public interface TaskManager {
Task[] getTasks();
public Task getRootTask();
void projectOpened();
public void projectClosed();
public GanttTask getTask(int taskId);

Could you please explain to me the different between 2 versions above? Description? What version 2.0 try to do and 2.1 try to do? Impact of the changes? Which taxonomy of code chages the version 2.1 belong to?
1. method of change
2. method parameter change
3. if statement change
4. variable change
5. constraint changes
6. calling dependency changes
7. new / delete method

Another one
Tasklistener.java
version 2.0
public interface TaskListener extends EventListener {
void taskScheduleChanged(TaskScheduleEvent e);
void dependencyAdded(TaskDependencyEvent e);
void dependencyRemoved(TaskDependencyEvent e);
void taskAdded(TaskHierarchyEvent e);
void taskRemoved(TaskHierarchyEvent e);
void taskMoved(TaskHierarchyEvent e);
void taskPropertiesChanged(TaskPropertyEvent e);

void taskProgressChanged(TaskPropertyEvent e);
}
version 2.1
public interface TaskListener extends EventListener {
void taskScheduleChanged(TaskScheduleEvent e);
void dependencyAdded(TaskDependencyEvent e);
void dependencyRemoved(TaskDependencyEvent e);
void taskAdded(TaskHierarchyEvent e);
void taskRemoved(TaskHierarchyEvent e);
void taskMoved(TaskHierarchyEvent e);
void taskPropertiesChanged(TaskPropertyEvent e);
void taskProgressChanged(TaskPropertyEvent e);

void taskModelReset();
}

Could you please explain to me the different between 2 versions above? Description? What version 2.0 try to do and 2.1 try to do?
Which taxonomy of code chages the version 2.1 belong to?
1. method of change
2. method parameter change
3. if statement change
4. variable change
5. constraint changes
6. calling dependency changes
7. new / delete method