In spiritual terms, the reception, dissemination and communication from non-physical planes to the physical plane.
A channeler on Earth is essentially an individual who can tap into the planes beyond this third dimension. The term as generally used does not differentiate between a psychic and a medium.
When a spirit guide such as Silver Birch or Seth manifests himself, there is a lessening of his vibrations. When such a guide temporarily leaves this plane to withdraw into the higher realms, he leaves behind an astral body, and resumes in his spiritual body which was cloaked down. Some portion of his consciousness is left in the astral body to prevent disintegration, but withdrawal into the spiritual body registers more and more of his inner consciousness. This kind of activity requires great sacrifice for it takes years (in our terms) to completely regain the full consciousness attained prior to returning to the world of matter.
When channeled Master Guides speak, they are often speaking to pupils of different stages on the path. They do not actually mean for you to take the whole, as a whole, but to take that piece of information which works. The same is true for this reference.
To make contact with your own guide can involve many different practices. A particularly powerful technique is to use one's creative imagination. By exploring the inner consciousness, quietly go within and ask to see your teacher. Be open and receptive to the images that may transpire and accept it as a dream symbol of one's teacher or guide.
Spiritual growth can take a considerable time. One should initiate meditation under guidance, and when ready, ask questions but listen and reflect on the answers.
The development of channeling should also be performed with guidance. Ground rules can be developed for the highest good for all. One must be fearless, as like attracts like.