what is the significance of delta H,S,G in thermodynamics

Answer 1

You need to refine your question a bit. Books are written on thermodynamics.

Answer 2

i mean can you explain the reason for the relationship (G = H-TS) and the defn for each

Answer 3

and sponteneity

Answer 4

I searched google.com and found a number of esoteric and highly theoretical discussions about thermodynamics. I know you want basic stuff; I found this one which seems to start from scratch and it appears they keep the math to a minimum. Here it is for you to read. This questions you have asked can not be answered easily on this forum without writing a book. Here is the link. If you want more information I suggest you google it.
http://web.mst.edu/~gbert/basic/thermo.html

Answer 5

ok thanks

Answer 6

Any freshman chemistry text will have good basic discussions also.