The terminology full-stack is meaningful to discern between an expert at one part of the stack and someone who knows how to set up and manage all parts of the stack. For example, consider the LAMP stack:
Linux
Apache
MySql
PHP
A Full-Stack developer is someone who knows enough Linux to set up an Apache server and MySql database, enough MySql to create a database, enough PHP to render a decent web page.
On the other hand, a frontend developer knows the gritty details about how to render a beautiful and performant webpage that works on IE6, iPhones on 2G and your 4k monitor.
The 'stack' in full-stack refers to a solution stack. You can read about them here: https://en.wikipedia.org/wiki/Solution_stack
The terminology full-stack is meaningful to discern between an expert at one part of the stack and someone who knows how to set up and manage all parts of the stack. For example, consider the LAMP stack:
Linux Apache MySql PHP
A Full-Stack developer is someone who knows enough Linux to set up an Apache server and MySql database, enough MySql to create a database, enough PHP to render a decent web page.
On the other hand, a frontend developer knows the gritty details about how to render a beautiful and performant webpage that works on IE6, iPhones on 2G and your 4k monitor.