A more thorough explanation:

An assembly is a group of people who come together for a common purpose. This can be a formal group, like a delegate assembly or a deliberative assembly, which follows parliamentary law to make decisions. It can also be an informal group, like a riotous assembly or an unlawful assembly, which can cause disturbances or break the law.

For example, a delegate assembly is a group of people who represent a larger organization and come together to make decisions on behalf of that organization. A riotous assembly is a group of people who gather unlawfully and cause a disturbance of the peace. An unlawful assembly is a meeting of three or more people who intend to commit a violent crime or breach the peace.

Assemblies can also refer to the lower house of a legislature in some states. In patent claims, an assembly is a collection of parts used to form a structure.

The right of assembly is a legal right that allows people to gather together peacefully and express their opinions. This right is protected by the First Amendment of the United States Constitution.