I've heard this phrase mentioned a lot, however i have yet to understand what it means, can anyone tell me?

Not sure, but I think it means play into your strengths, and don't fall into their's. This applies to both the champion and the player. For example, don't walk into melee range against a Darius if you're at low health. And the other way around, as Darius, try to GET into melee range of them. And if its for the player, take notice of how they play. Some people telegraph ganks a TON. Then, when their lane behavior changes, you know when to back off.

I think it means your champion does well against the opposing champion.
An obvious example would be Galio vs Annie.

its when u have countered ur opponent as inexample.
Yorick worst counter jax yorick in favor in the lanr
Vladimit in favor against morgana
This is really just what i think pff

As an adjective, if a lane is "in your favor" it probably means you have an advantage against your lane opponent. For example, a champion that counters theirs, or maybe you have a jungler camping your lane and they don't.

As a verb, to "lane in your favor" probably just refers to smart laning. Not pushing unnecessarily, zoning properly and not getting zoned, coordinating with the rest of your team...etc. I think this is what most people are trying to say when they tell you to "lane in your favor." Play smart so you don't have to play the keep up game.

Close, it means you are winning lane. That's all. It could be picking teemo vs darius and you are winning at lvl 1. Or if that darius picks up 2 killls then its in his favor.