In politics an assembly can refer to any body meeting together to discuss matters. A parliament or a legislative assembly such as the French revolutionary Legislative Assembly. Or it can be a body more designed to mediate between otherwise independent bodies, such as the United Nations General Assembly.
Schools also sometimes have an assembly collecting the students together for prayer and song.
In mechanics, architecture and electronics assembly is the action of putting together the separate parts of what is intended to be assembled. Modules, components or elements or combinations of such may be the objects of the assembly. "Assembly" may also refer to the whole that results from such action.