A virtual appliance can offer network services, such as content filtering and enhanced security, running as software on virtualized environments. This allows the company to utilize existing servers and reduces the need for additional physical hardware, aligning well with the desire to expand services without substantial hardware investments. A router or switch, although crucial for network operations, primarily focuses on traffic directing and switching respectively, and not on providing the additional services mentioned. A proxy mainly serves as an intermediary for requests from clients seeking resources from other servers.