Thread in this context means any particular topic for conversation between a group of people. So this facility allows user to talk to administrator and his empoyer. Every one can create a new topic by adding new thread with proper subject line. Then the conversation could follow as per the response added by user, administrator or employer. This way it is very easy to follow up with the conversation on a topic.
When a new thread is created by administrator or employer, you will see the [ New ] indicator image next to the thread subject. You should immediately view the thread by clicking on the subject.
When you click on any thread subject to view it's content, there will be a text box at the end to add your response. Write down in the text box and click on submit button. You will see that your matter will be added to the current thread.