Pane is a term that can refer to several different things, depending on its context.
In general usage, pane refers to a thin flat piece of material, such as glass or wood, typically used for windows or doors. In this sense, it's the singular form of "panes," which means multiple pieces of glass or other materials that make up a window.
However, in some regions, particularly those with strong Italian influences, pane can also refer to bread. This usage is derived from the Italian word for “bread,” and refers specifically to a type of soft white bread commonly consumed throughout Italy and parts of Europe.
In addition, "pane" can be used as an informal term in some regions to describe any flat or thin object, such as a piece of paper or cardboard. This usage is more colloquial than the others and isn't typically found in formal writing.