From my head on portable storage containers
It wasn't so long ago that your only options when you wanted to move was to hire a transport service who will pick up your things and bring them to your chosen location. This worked well for the most part, but it did have a number of significant drawbacks. For one thing, they could be very expensive. For another thing there is the issue of having to conform to the rigid schedule of the moving company. In addition, you may be charged extra for going over the packing scheduled by even only a few days.