It is the sultan of instruments for the Arabs and the origin of lute is perhaps the Arabian oud, a pear shaped instrument.
From the Arabs it came to Europe who made it their own.
Now what exactly is a lute?
In simple words, it is any instrument that reminds you of the guitar. Same properties -- long neck, strings running parallel to the sort of round sound body, strings that can be plucked, a long neck and a sort of roundness to the body. Our lute looks somewhat like