What is the meaning of Sidebar?

A short news story printed alongside a larger one.

A block of information placed at the side of a printed page.

A block of information placed at the side of a webpage.

A short conference, between a judge and the attorneys of a case, held outside the hearing of the jury and the spectators at the court.

The place in the courtroom where such a conference happens.

An accessory side note or aside made during a conversation, without changing the scope of the audience.

A short conversation between a smaller portion of a group held outside the hearing of the rest of the group.

To place (information) into a sidebar, or as if into a sidebar.

Source: wiktionary.org