Much has been written about guardian Angels over the centuries.
There tends to be a consensus that it is non-physical and is constantly protecting the individual.

I propose another description based on the accumulated attributes by many different belief systems and authors.

The physical universe is fundamentally energy. We find it is made of vibration/frequency as is all matter.
At the human level, this body and mind is also made of vibrating atoms that differentiate into each of the parts. We are basically electromagnets!

What makes each of us unique is the frequency we vibrate. The time, location and inherited genes at birth dictate what that frequency will be. But here is the part where the Guardian Angel plays its role.
From the moment the baby takes its first breath the frequency is fixed. That is because the universe (many call this god) is pressing on all sides but only the frequency that matches that time/location/genetic code will vibrate in that baby.
This unique frequency is intelligent, aware and non-physical. This is your Guardian Angel. It is literally surrounding you, on either side, ahead, behind, above and below. It is a supernatural being – to use a common term.
Its frequency has been tuned by all past lives which knowledge is carried in the frequency.
We personify it with human characteristics and human appearance, which helps us to relate to it.

The Eastern religions that talk of Karma are describing the past life actions that resulted in this particular frequency. Your essence and your Guardian Angel are identical. When your physical dies, your Guardian Angel withdraws because there is no body (heartbeat) to vibrate. You and you Guardian Angel are one.

Depending on your actions and thoughts in the physical body the frequency will have changed (or not). This will again enter a body when the time/location/gene frequency are a perfect match. This is reincarnation. Once the frequency is no longer slow enough to affect physical matter you/your Guardian Angel will ascend to Heaven. Again, this is all frequency, albeit intelligent and aware as are all frequencies.

Communicating with your Guardian Angel is not talking to yourself. Language is not used. You are only aware of it at a subliminal level, most commonly experienced as conscience. Pinochio’s Jiminy Cricket is one example. It guides you via your heart and breath. If you listen to your heart you will be guided by your Angel.