What is a dry sense of humor?

Question

What does a dry sense of humor mean?

This article explains how to develop it, but not what it is.

How to Develop a Dry Sense of Humor

Developing a dry sense of humor can be challenging and fun. Learn how to develop one. If you really want to (and you know you do) then read the article.

Answer 1

Here is a relevant definition that says it all:

dry adjective
(of a joke or sense of humor) subtle, expressed in a matter-of-fact way, and having the appearance of being unconscious or unintentional:
he delighted his friends with a dry, covert sense of humor

^NOAD

Answer 2

The article itself is an example of dry humor.

Answer 3

It should mean being sarcastic and ironic.

Check my answer here: The word ‘dry’ as an adverb