What is the origin of the idiom "from pillar to post" and when to use it?

The idiom "from pillar to post" is believed to have originated from the practice of punishment in medieval Europe, where a person would be tied to a pillar or post and then whipped or beaten before being sent to another pillar or post to receive more punishment. Today, the idiom is commonly used to describe a situation where someone is being sent from one place or person to another, often with a sense of frustration or confusion about why they are being moved around.