sir iam confused what is difference between kernal version my aex stock kernal is 3.18.110 but in linage is it is 3.18.71 did version of kernal affect battery. ........... I mean that more version of kernal means more battery life or not plz tell me detail I'm confused
The kernel version numbers don't have anything to do with battery life. The versions indicate newer code releases that have bug fixes, security updates, performance fixes, additional functionality etc. for the low level software that interfaces with the phones hardware.
For example, LineageOS extended edition is currently on 3.18.113, which is even newer again.
Updating Kernel sources - which is to do with Linux kernel sources, is different from just Android updates, which is to do with the Aosp libraries placed on top of Linux to provide us with an interface to run Android applications and software on top of a Linux base platform. In addition to this you can have other libraries such as LineageOS api, that provides more functionality over Aosp.
Hope that helps you.
There's other interfaces / libraries that can run on top of a Linux kernel, and if you look at what is happening with Chrome books now, you can see that not only are they able to run Android apps, but Google is now opening up running regular Linux applications on top of the underlying Linux Kernel, in addition to ChromeOs applications.