You can use the device as both a computer speaker and a bluetooth speaker. That's what I do. I have the speaker on the desk for use with the computer when I am at the computer and then take it off the base for use in other locations. You can use it in either Bluetooth or Aux mode. In Aux mode you just use a speaker wire and plug it into the computer directly. (Wire not included). Then you can move it and use it in bluetooth mode.
In fact I have the speaker synched to my iPad for bluetooth use and directly connected to my Mac for desk use. When setting on the base the speaker will initially draw from the battery, but then start drawing directly from power base and lasts all day that way.
Battery is extremely long lived though. I have used mine for over 7 hours without it being exhausted.