The second instalment in this trilogy of articles explaining some of the more common terms found in networking jargon introduces two terms which may already be familiar to many computer users as technologies they make use but without necessarily a full awareness of their definitions: Ethernet and VPNs. Ethernet The term Ethernet is most frequently used to describe a type of network cable, common in our homes and workplaces, but actually applies to the protocol which defines the cable and its associated technologies (e.g., computer ports) that can be used to connect computer devices to each other within a network. As a result the term can even be used in some contexts to refer to the networks (predominantly LANs – Local Area Networks) themselves that they form. The Ethernet protocol is standardised by the Institute of Electrical and Electronics Engineers Standards Association (IEEE) and is the most common such network connection used in the IT industry. The original Ethernet standard delivered a data transfer rate of 10 megabits per second and utilised copper coaxial cables (i.e., inner cable which carries signal is insulated by secondary sheet material) to do so. With the advent of successive standards such as Fast Ethernet (100 Mbit/s) the transfer rates have risen significantly up to the highest at 100 Gigabits a second. The Ethernet cables used t0o achieve these speeds have developed to include fibre optic and twisted pair (usually copper) cables alongside the original coaxial forms, with the most common and familiar cables in the home and workplace being twisted pair. VPN The abbreviation VPN is short for the term Virtual Private Network. This concept covers a broad array of technologies, including EVPN (Ethernet VPN), but essentially describes a secure connection between computers or LANs made across a public network such as the internet. VPNs allow communications between separate networks to be kept private and secure with no-one intercepting them and/or viewing them in transit. Whereas secure WANs may have previously relied (and in some cases still do rely) on dedicated physically distinct leased lines to ensure that the information being transferred is done so outside of the public domain, VPNs create what is called a tunnel to provide the same effect. VPN tunnels are a virtualised equivalent ‘through’ which encrypted data packets are transferred – essentially representing the idea that the data packets are cloaked to appear as though they are normal public network data transmissions without providing any visibility of the data they contain. The packets containing the core data are encrypted and encapsulated within outer packets which are further encrypted and which simply display information on which network gateway they are intended. The encrypted packets of data can only be unencrypted to view the contents when they reach the predesignated destination computer. VPNs are a vital tool in business to allow workers to work securely off-site (as if they were in the office), to connect disparate branch offices, reduce physical business travel and to allow networks to incorporate and utilise varying types of computing device (e.g., tablet vs desktop). In turn, these opportunities all allow businesses to increase efficiency – reducing costs and boosting productivity – as well as improving flexibility and employee morale.