It’s part of the language localization function. Anything inside that function will have a corresponding equivalent in all the other language files that are available for WordPress.
Does the reader’s selected language have any impact on this? Meaning, if someone in, say, China is reading my site, will things inside the _e() function be translated into Simplified Chinese? Or does this rely on the language selected in the WordPress options?
No things are not translated on the fly. Your set your language to be used on the blog in wp-config.php and if there is a language file available, you’ll see all the WP goodies in that language.
Okay. So, if I were designing my own template, I could, technically, do without those function calls. Is including them part of the WordPress coding ethic?
Including them would help someone who might wish to port your template over to their local language. If you don’t want to include them, then you don’t have to. WordPress includes them in order to make the product useful to the widest audience possible.
Okay. Thanks Nuclear Moose.