To create a VLAN, an Ethernet switch can be configured to group ports into numbered VLANs. For example, when packets arrive on port #9 (VLAN #1), the switch can push those packets through all other ports belonging to VLAN #1, and only those ports. This simple, static approach is known as port-based VLAN.
Business casual is an ambiguously-defined dress code that has been adopted by many professional and white-collar workplaces in Western countries. It entails neat yet informal attire and is generally more casual than informal business attire but more formal than casual or smart casual attire.
Formal attire is clothing that is appropriate for extremely formal events, such as weddings, dances, and other special occasions. This type of attire can generally be broken into two categories: white tie and black tie. Determining what to wear to a formal event also depends on the time of day and context of the event. Unless an invitation specifically states otherwise, formal attire usually means a tuxedo and black bow tie for men and an evening gown or very smart cocktail dress for women.