system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is the point of XML?

I have a great understanding of database systems, HTML and CSS but I after reading for hours and even watching videos I cant see why anyone would ever use this.  It does not seem an appropriate or efficient way to deal with data.
gpt
XML is a well defined, general purpose, data transfer language that's designed to facilitate the transfer of data from one system to another in a standard way.  Before XML was a thing, every program had its own protocol so you'd have to write new parsers for data import or interchange between every system.  XML is basically HTML intended to be used for machine-readable data.

It's not intended to be efficient from a CPU or space perspective.  It's intended to be a single, easy to work with standard so that all systems can transfer data between each other using a standard XML parser to interpret the data - it's efficient in terms of *programmer time*.

Whether it's actually effective at this is a matter of debate.