The Best Way to Build Custom Meta Boxes in WordPress?

Recently I needed to accomplish a specific chore for my job. I needed to make a meta box in the WordPress admin.
The image below shows an example of a simple meta box. In WordPress, in the admin area, any box that holds a part of the User Interface is called a meta box.




[[ This is a content summary only. Visit http://OSTraining.com for full links, other content, and more! ]]