A Simple Question
The question, ‘What is a dowser?' will often be asked by someone who is either a total newbie (and that's OK, we all were once), or someone who only heard of dowsing in the previous 5 minutes.
It is a question with two possible answers, either of which can be correct.
What Is A Dowser? Two Answers
One of the simplest tools you can make to dowse with is a small nut on a piece of string or dental floss of what-have-you. It has led to the description of dowsing as being about ‘a nut on the end of a piece of string.'
That description is, of course, deliberately double-edged. The nut on one end of the string is the tool. and that could also be called a dowser, because it is the thing which shows the dowsing response.
On the other hand, of course, the other meaning of the ‘nut' is the person holding the string. And that person can also be called a dowser, because that, presumably, is what they are doing.
So the answer to the question ‘What is a dowser?' can be found at either end of the tool. :-)
But don't think you have to be a ‘nut' to dowse. Far from it! In fact, I think it takes a good deal of sanity to start dowsing…
You can watch this video about what is a dowser to see the answers to the question.