android-tabhost - what is the relation between TabHost and TabSpec..Is Tabhost a superclass for TabSpec..Also I want to understand the code given below

Question

TabHost th=(TabHost) findViewById(R.id.tabhost);

th.setup();

TabSpec ts= th.newTabSpec("tag1");

can anyone please tell me what is the significance of new in newTabSpec and and how th is being used in this code for newTabSpec