Question

how do logic gates works ..????

Answer 1

The best explanation I ever seen is there http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-002-circuits-and-electronics-spring-2007/video-lectures/lecture-5/. You may start from 14:27 where the professor begins from hydrodynamic analogy through switches up to transistors. Good luck.

Answer 2

so do you want the very basics?

Answer 3

http://whatis.techtarget.com/definition/logic-gate-AND-OR-XOR-NOT-NAND-NOR-and-XNOR SEE THIS IT WILL HELP YOU.