system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What do artists mean when they talk about rendering?

I hear the term "rendering" thrown around in both traditional and digital art communities like it's some sort of buzzword, but I've never gotten a clear explanation as to what it means.
gpt
Think of the work you do in the software like a pencil sketch of an idea  
You get everything where it needs to be and laid out,  
but then you need to ink the sketch, do coloring and shading. Thats rendering.  
If you render a low res work....say a southpark episode. The computer has almost no shading to do, the colors are simple fills, and shadows rarely exist. The rendering speed can approach real time.  
If you want to render a photorealistic world, with photorealstic people every object is coated in a high resolution skin, the computer needs to create all the shadows and highlights the sources of light demand...and you want 23fps?..and your rendering times stretch out into YEARS of processing time on your weaksauce laptop.  

So you pay to have rendering done at a server farm where hundreds of computers will each chip away at seconds of your footage, returning results....well just about as fast as your wallet allows.   

In olden days, animation shops would send their work to cheap foreign sweat shops for dozens of low paid third world artists to "render their ideas a reality in ink and paint" For computer graphics those sweat shops are render farms.