What makes something low-level?

This is a vague term, let's say it pertains to things like:

• C programming, or any kind of systems programming where you're pushing bits around
• Assembly programming
• Chip architecture
• Virtual Machine design
• Compiler and/or langauge design

Something seems to be "low-level" when it's in closer contact with the "real world"

But an html login form is very much in contact with the real world, and most wouldn't say that writing an HTML form is low-level.

So, I think low-level is probably talking about levels in terms of the Open Systems Interconnections model.

i.e. anything pertaining to layer 1 (physical), or maybe layers 1-4 (physical -> data link -> network -> transport)