Steam cleaning is a cleaning process which uses hot water and steam to remove dirt. Steam cleaning is especially effective when it comes to hard to clean areas, such as carpets. In order to remove dirt, the steam cleaner puts the steam through high-pressure jets that separates and loosens the fibers lodged in the carpet.
Since steam cleaning loosens the fibers, steam cleaning is a much more effective way to clean than cleaning by using vacuum cleaners. Vacuum cleaners only clean the surface area of the carpet, whereas steam cleaners get right in there and make sure the carpet is removed of all dirt and grime.
If you are looking for an office cleaning, make sure that they provide steam cleaning, since this is a much more effective way to get rid of dirt compared to just simple vacuuming.