Native templates
Templates are patterns for how we merge data and the stuff the data fits into. The most popular form of templates on computers in the early days was something we called a mail merge. Programs like Microsoft Word would use a mail merge document and a data file, and merge them together. The original purpose was for printing.
Over the time, we shifted to using this same type of technology to do web pages. When a user would go to a website and request a web page, the servers started getting smarter. The data was mixed into a template and the merged result was returned to the browser as HTML. This was an amazing game changer for shopping sites and other sites where the basic page was the same. This is why we call these pieces of code templates.
One way to look at this is to think about when people decorate houses. We have things we call stencils. While the stencil defines how the shape of the result will look, it does not control what color you paint something with. If you have...