Clients may be permanently connected (often known as “always-on”), or may connect dynamically when needed.

Permanent connections are most commonly made through a local area network (LAN) or a digital subscriber line (DSL or ADSL ), and give instant 24/7 access.

A temporary, dynamic connection such as that provided by a modem link needs to be connected each time the Internet is used, which can cause a delay. Modem links also tend to be slower than dedicated digital links, because they use normal voice telephone lines which are not designed to carry digital signals.

DSL connections also carry a digital signal across wiring designed for analogue signals, but do so by overlaying a very high frequency signal (well beyond human hearing) onto the normal connection. This means that not only can the same line carry voice and data simultaneously, but that for short distances, a much higher bandwidth can be carried.

Dedicated wiring for Internet traffic is most commonly found in companies and other organisations, where a LAN is used to connect clients and hosts together. Usually, this forms an enclosed network which connects to the outside world through a single point, which can be controlled and protected against intrusion and viruses. Connection to this type of network is normally instantaneous and 'always-on'.