The etheric body is essentially your life force. It can be equated in the Hindu tradition as the 'envelope made of prana', or in the Chinese tradition as qi.
The etheric body is popularly referred to as the 'body of energy', or 'energy body.'
An excellent source of information on the etheric body is found in a text called Subtle Bodies where the distinction can be made between the physical or more solid body (eg bones), the layer of life force, and the astral body - that which is thoughts and emotions. The meridians of acupuncture are circulations in the etheric body, same with the nadis of the Indian tradition.
The etheric body is within the body and has layers outside the body. When a person speaks about an aura, they are talking about a layer of the etheric body. Although when speaking about an aura, not everything about the etheric is the aura - so the terms should be separated.
The term etheric body is used extensively in anthroposophical literature. Due to the comprehensive work of Rudolph Steiner, the term etheric crossed over into many other spiritual systems and was subsequently adopted by many eastern traditions. Hence qi, prana and etheric are broadly speaking about the same substance.
Also there is the experience and practice of etheric sensing. This is a form of perception and is practiced extensively by spiritual traditions and is documented by a school of meditation known as Clairvision, (where I have trained and continue to be a student.) Etheric sensing is a resonance from etheric to etheric. Examples of this are sexual attraction. Also when you walk past something and sense something is wrong - like a plant needs watering because you feel it is dry and is crying for water. Knowing what vegetables to pick up in a supermarket because they feel more vibrant. Feeling blockages within your own body. Gut feelings can be put in the category of etheric sensing.
When a person rubs their hands together vigorously and then stands them apart several inches, you will feel a vibration between them. This is the etheric, or life force. When a person practices reiki (to use a common example of healing) and lays their hands close to the client's body and senses energy - they are sensing the etheric body.
Ref: A language to map consciousness. Dr S.Sagan, 1996-2011
Obviously I should do a hub on this!