According to ubuntu help section, tasksel is a command line application that can be used to install tasks. Here a task is nothing but meta package for other packages. Except that you can define your own tasks by editing the file /usr/share/tasksel/ubuntu-tasks.desc.
Tasksel presents curses based interface by default if you don't specify any command line arguments. Following are some of the predefined tasks you can install.
You can get complete list of tasks by executing following command.
Here is the command to install any given task.
sudo tasksel install [task name]
Enjoy ubuntu :)