In stabilizing the position of the camera the photographers might need a monopods as one of their useful devices. In condition with a very low light, they would require a longer period of time as the shutter has to remain open in good stability.
Within the time taking duration is long enough, a big chance of having a motion in the result may appear later in the result as it is taken without it.
Though, it can be the element that is wanted to be made in the picture and even it can also be something that is unwanted because of the blur that is appearing.
In this case motion makes up two reasons, the first one is that people that moves along the shutter period of time, or the camera position whe the picture is being take that is controlled by the photographer.