Hello, I am in a wheelchair.
Too bad, it is  used when walking is difficult or impossible due to illness, injury, or disability.
Yes it is. I was paralyzed in a car accident many years ago.
They come in various shapes and formats so as to meet the need of the user
Yes, mine is rather basic, and has experienced much wear and tear, but it works for my needs.
oh ok. Some have  specialized seating adaptions, individualized controls, some even have technology friendly features these days 
Yes, fortunately for myself I still have use of my arms, so controls are not needed.
where the propulsive force is provided either by the wheelchair user/occupant pushing the wheelchair by hand ("self-propelled"), or by an attendant pushing from the rear ("attendant propelled").
History.
The earliest records of wheeled furniture are an inscription found on a stone slate in China and a child's bed depicted in a frieze on a Greek vase, both dating between the 6th and 5th century BCE. The first records of wheeled seats being used for transporting disabled people date to three
Wheelchair
A wheelchair is a chair with wheels, used when walking is difficult or impossible due to illness, injury, or disability. Wheelchairs come in a wide variety of formats to meet the specific needs of their users. They may include specialized seating adaptions, individualized controls, and may be specific to particular activities, as seen with sports wheelchairs and beach wheelchairs. The most widely recognised distinction is between powered wheelchairs ("powerchairs"), where propulsion is provided by batteries and electric motors, and manually propelled wheelchairs,