Template variables are special tags which will be processed and replaced with datas from database or from language files when the script is running. The template variable has the structure like this: {SOMETHING}. Here are some examples:

+ {L_YOUR_NAME}: will be replaced with the language variable (Ex: "Your name").
+ {L_YOUR_EMAIL}: will be replaced with the language variable (Ex: "Your email").

+ {ARTICLE_TITLE}: will be replaced with the real article title.
+ {ARTICLE_CONTENT}: will be replaced with the article content.