In simple terms, Polishing Concrete is similar to sanding wood.  

When sanding wood, you would start by sanding with more aggressive sandpaper then move to finer sandpaper, and so on until the surface is smooth.  Each step removes scratches from the previous step.  This is similar to Polishing Concrete.

With Polished Concrete, we use approximately 7 grinding/polishing steps, including 1 step of hardening/densifying and the final 2 step process of adding the sealer and burnishing.  

We begin the process by grinding with “metal/diamonds” to remove the “cream” or “cap” of the concrete surface so you can begin seeing the rocks or “Aggregate” below.   This often provides you with the “salt and pepper” look.  This step is the longest may take days or even weeks depending on the square footage and type of concrete (hard vs soft). After the preferred aggregate is achieved we then harden/densify the concrete during this process while the concrete pores are still open to accept the hardener/densifier.  This gives your floor more life, durability, and sheen.  After the necessary steps of metal grinding and densifying are complete, we move to resins and start to hone and polish the floor to a natural glossy shine.  

The resin steps are then where the concrete surface begins to smooth and polish and you begin seeing reflections off the surface of the concrete.  We then polish the surface to your preferred polished concrete specification of gloss level.

The process usually takes about a day per 500sf and typically a minimum of 3 days on any surface being worked on.  The density of the concrete, the patching, as well as the crack and joint treatment may also add days to the job as well.