Yes, they represent absence of electrons. You have to get into solid state chemistry to start really making sense of what's going on.

Neutral silicon has four valence electrons (the "outer shell" of electrons). To conduct electricity, these electrons need to be pushed up from the "valence band" to into what is called the "conduction band". See here:

https://qph.is.quoracdn.net/main-qimg-3bfa430f09c3689f39774fdbbb5db7ae?convert_to_webp=true

Basically this picture shows the two bands. Vertical axis is energy level... so simply put if you give the electrons in the valence band (default energy) more energy, you can put them into the conduction band.

N-type semiconductors are silicon which they add a very small amount of atoms with 5 valence electrons. These "extra" electrons end up being somewhere in between the valence and conduction band... typically very close to the conduction band.

http://hyperphysics.phy-astr.gsu.edu/hbase/solids/imgsol/bandop.gif

Therefore, you need less energy to get those electrons into the conduction band.

P-type are doped with atoms that have 3 electrons. Therefore, you have a bunch of spots where electrons liberated from the silicon atoms can easily "fall into". We call these holes, aptly enough. by increasing the energy of the valence band electrons, they fall into these holes quickly and start conducting... But they aren't in the conduction band... and they conduct a bit differently.

Imagine an infinite row of atoms. One of theses atoms is missing an electron and is happy to get another one. If we give the electron in the atom next to it enough energy to break free, it will naturally want to fall into that hole. Now the atom that gave up the electron is missing an electron and wants another one! The next one in line may then lose it's electron and so on... What you end up with is a "hole" moving backwards in the line, even if the "hole" movement is really just electrons moving the opposite direction in order to fill the hole (and thus creating another hole). Despite this reality we can still treat the "hole" as a sort-of-positive charge even though its just an absence of a negative charge... doing so might be weird to think about, but it makes a lot of sense in the math to describe it.