You'd have code that would "draw thing 1", move, then "draw thing 2".

Modern pipelines instead have you upload your vertex data to the GPU and write shader code that tells the system how to draw it. They become managed by the GPU and your code cares less about explicit drawing.

Another way to look at this is that "immediate mode" feels much more imperative than the modern asynchronous graphics pipeline. You tell the system to draw or render something, and it immediately does so.

This post has another good explanation with simple code:

https://stackoverflow.com/questions/6733934/what-does-immedi...

It's much easier to wrap your head around immediate mode though, and several tools with this imperative/immediate philosophy (such as imgui) are popular.

Edit:

Here's a fantastic comparison: https://cognitivewaves.wordpress.com/opengl-vbo-shader-vao/

(See "Immediate" vs the more modern code that follows.)