For me "raising my vibration" simply means moving myself to a better feeling place, and hopefully radiating that outwards.

When I raise my vibration or move myself to a better feeling, I emanate a much lighter energy and as a result who and what I attract will resonate with that energy, bringing into my life more of what I desire and more opportunities for growth.

What is vibration?

Vibration is a measurement of the movement of energy expressed as frequency or rate of vibration.

What does "raising your vibration" mean?

It means increasing the frequency or rate of your vibration.

And what is its significance in spiritual growth?

Raising our vibrational frequency enables us to resonate at a frequency that is nearer to that of our higher self. As we vibrate at higher and higher rates, we re-connect or re-member with our higher self and can thus operate more directly from the perspective of our higher self and our ego-self or personality has much less influence on our decisions.

In my view, we are the imagination of our higher self, but due to our generally low frequency awareness, we've been unconsciousness of this fact. So raising our vibrational frequency is really a journey home, home to where we've actually always been. Feel it 8-)

I agree with what the others have said but there is a bit more to it. Raising your vibrations can be interpreted on two levels. At the level of the physical or conscious mind, it means changing the way we feel or think. At the subconscious level or at the level of 'source' it is pure energy which comes to together to form molecules, atoms and cells until it manifests in the physical.

Vibration is pure energy moving around in our universe, and you can feel the movement in it.

When your vibration is moving you to accelerate in your academic achievement and you suddenly get a promotion in the work place, you know that you are in a higher place for sure.

Also when you can connect with this vibration, and you can identify with the spiritual aspect of the LOA working for you in a certain way, you would have come to realize that you have made a spiritual connection in your life, with this source of energy!

Vibration is a measurement of how one is feeling. Being in "High-Spirit" means you're raising your vibrations. Which is quite significant for spiritual growth because it 'lightens you up' :)

Thank you, namaste