Howdy is an informal greeting, commonly thought to have originated as a shortened form of the greeting "How do you do?". It was first recorded as part of the South England dialect in 1680. Literature from that period includes the use of "How-do, how-do" and "How" as a greeting used by the Scottish when addressing Anglo settlers in greeting. Hello The double form of the idiom is still found in parts of the American Southwest as "Howdy, howdy". Without regard to etymological beginnings, the word is used as a greeting such as "Hello" and not, normally, as an enquiry. Yes, As a result, it's not followed by a question mark. Punctuating "Howdy" commonly follows these rules: (i) If "Howdy" is used as a complete sentence, it's followed by an exclamation mark. (ii) If "Howdy" is the first word in a sentence, it's followed by a comma.
In the rural Southwestern United States, "Howdy" is a colloquial contraction of the formal greeting of "How do you do?", and as such is considered a formal and acceptable greeting for residents of that region of the world. "Howdy" is also the official greeting of Texas A&M University.
The word became recently popular in other areas of the world as it is the default greeting from the dashboard of WordPress, a very popular content management system. The probable reason for using "Howdy" (instead of "Welcome" or "Hello") in the dashboard is because Matt Mullenweg, one of the main developers of WordPress, was born and raised in Texas. Some developers have created Plugins to change the default behavior and use another greeting instead.