Some fabrics can be too fragile for use as upholstery unless knit backed. Knit backing is a process whereby, for example, a cotton polyester backing is applied to a lighter weight chenille, silk or cotton.
Essentially the fabric‘s life is increased with better durability and resilience. The handling characteristics of the fabric can be improved; and knit backing also helps prevent seam slippage.
The same principle applies for the fabric whether or not it is to be used for either upholstery or wall covering. There will certainly be other requirements for contract usage, say, in hotels and aviation and also other treatments like fire retardancy or stain protection would be required for contract upholstery.