The structural components of the lute are similar to those of the modern guitar: strings, a neck, frets, a soundbox, and tuning screws (machine heads).
The origin of the lute is obscured by definitional debates, which are really a waste of time. Instruments with strings and a soundbox go back to the hunter-gatherer times of humans - such as the bow - and structurally all later instruments with the same architecture are basiclaly just design variations of the same structures, no matter what names are used. Just as different guitars have acoustically different sounds due to the minute differences in harmonics caused by different materials and cavity spaces, the lute may be regarded as just another variation on this basic design.
Source: http://www.miayf.org/string/plucked-string-instruments/the-lute-family/
http://www.earlymusic.co.uk/general/prod_8.htm