Hello Sameer,
I already addressed this. You can not learn these things in one thread. Also please note that one is supposed to know these fundamental things before he starts participating in SCN.You need to learn these things from your surroundings (usually ABAPers). A very basic thing to find about the field name and the table which it belongs is through F1 key . i.e., You will press F1 key of your keyboard while keeping the cursor in the field. Then from the Technical information icon of the help screen you will come to know these things.
Also go through this post:
How to find Table name for a Field which is shown structure name on press F1.
You get plenty of such material here (Go through maximum number as you can while exercising in system). Always search Google the referred link here is searched.
Good luck
KJogeswaraRao