The vacuum cleaner sucks in the room's air as well as the dirt on the floor due to its operating principle. You'll also need to blast that out somewhere. This process agitates the dust by moving the air in the room.
The air coming out of the vacuum cleaner, on the other hand, may contain dust particles and other toxins, which are dispersed throughout the room and inhaled. To prevent this, it is a smart option to install an air filter in the appliance. It can be a sponge-like sheet in less expensive equipment, but more complex machines currently use water or advanced HEPA filters. Filters can be purchased from any vacuum shop, both physically and online.