Skirting boards are one of the weird things that you don’t notice until you don’t have any. Generally skirting boards are there to protect the bottom of the plaster and to hide any gap between the floor and the plaster, providing better insulation and protection from dust.
Fitting skirting boards can be tricky and is something that the less experienced renovator might want to call in a carpenter to help with.
Read more about this - how to fix skirting boards to the wall.