noun
stool
STOOL/stuːl/
A seat without a back or arms.
A plain wooden stool stands beside the workbench.

Etymology
The ancestral word meant a seat for one person and could even name a throne. As chair gained ground, stool became restricted mainly to smaller seats without backs or arms.
In context
you might be inclined to pull out the bar stool in front of you and take a seat at the counter