What is coding?

It's not a medical emergency, not that kind of coding.  It's computer coding.  It comes in several languages, the most popular being css, javascript, and html.  But, it's been adapted into blocks for learners and has become a popular way to get kids to use critical thinking skills as they problem solve and create.
 
For children as young as primary grade students, coding programs like Code Studio offers toolbox blocks use cardinal directions (north, south, east, west) to move characters, while others use "left" and "right" as direction words.  These help children develop reading and map skills.  Other standards that are addressed with some serious impact are the mathematical practices.  Coding addresses the following CCSS Mathematical Practices for grades K-12:

MP1: Make sense of problems and persevere in solving them.  "They monitor and evaluate their progress and change course if necessary."

MP2: Reason abstractly and quantitatively.  They are able to "contextualize, to pause as needed during the manipulation process in order to probe into the referents for the symbols involved."

MP4:  Use appropriate tools strategically.  "They are able to use technological tools to explore and deepen their understanding of concepts."

MP7:  Look for and make use of structure.  They "can step back for an overview and shift perspective. They can see complicated things, such as some algebraic expressions, as single objects or as being composed of several objects."

MP8:  Look for and express regularity in repeated reasoning.  "Mathematically proficient students notice if calculations are repeated, and look both for general methods and for shortcuts."

The results are instantaneous and rewarding.  Below are screenshots of Bee Loops, a coding game in which I successfully coded using as few blocks as possible by embedding five steps into a repeat block that I programmed to repeat three times.  It sure takes some critical thinking, folks.  Try it out for yourself at Code Studio (code.org).

Reference:  Common Core State Standards Initiative.  http://www.corestandards.org/Math/Practice/