YAHOO ANSWERS TOOK MY PREVIOUS QUESTION DOWN SO NOW I HAVE TO ASK AGAIN - does it need it to vacuum
What vacuum cleaner do you own? For the majority of vacuums the answer to your question will be yes, you will need the hose inserted into the holder for the base part of the vacuum to suck/clean properly. Some vacuums will keep the beater bar spinning, but that doesn't mean it is creating suction/air flow. If you give your vacuum model then I could be a little more specific... Good luck!
It completely depends on the vacuum cleaner whether the hose must be in place or not for the floorhead to have suction. Most of the cheap vacuums require the hose to be holstered because suction is through the hose, not other ducting. Dyson is an example of a vacuum that can be used with or without the hose in place.
The vacuum cleaner operates through the hose. If you remove the hose you can add attachments for cleaning crevices and upholstery. The floor part of the vacuum will have no suction. When you replace the hose you will have suction through the vacuum part and you can use it for carpets and rugs.