Ethernet and universal serial bus (USB) are both standards that computers can use to transmit data. The primary use of Ethernet is to connect computers and devices to local area networks (LANs). USB is typically employed to connect a wide variety of peripherals to computers, which can include devices such as hubs or adapters. If a computer lacks an Ethernet card, an Ethernet to USB adapter may be used to connect it to a LAN. Another potential use for these adapters could be plugging in to a high speed modem that does not have a built in USB port.
Many computers come equipped with Ethernet ports to facilitate network connectivity. These ports are available on many motherboards, in which case no additional Ethernet card is required. If a computer lacks an Ethernet port, it can be difficult to tie it in to a network or access modern high speed Internet. The two solutions are typically to install an Ethernet card or use an Ethernet to USB adapter. Some applications, such as laptops, may not allow the installation of a card, while in others an external adapter may be the easier route.
There are two main varieties of Ethernet to USB adapter. The simplest form typically consists of a male USB plug and a female Ethernet jack, along with the necessary electronics to join the two. This type of connector can be useful if the computer has a number of unused USB ports and lacks the ability to plug in to a router or modem via Ethernet. Of the two types of Ethernet to USB adapter, the simple one to one variety is typically the less expensive.
In addition to simple adapters, more complicated Ethernet to USB hubs are typically available as well. These units may be powered using the USB connection or might require an external source of electricity. A hub unit will typically have a variety of different ports, including an Ethernet jack and one or more USB connections. This type of Ethernet to USB adapter can be useful if the computer has very few USB ports, or if several devices must be connected at once.
Some circumstances may require a second network port, which is another way that an Ethernet to USB adapter can be used. One potential use for multiple Ethernet ports on one computer is to share Internet access to a second device, which is typically achieved by bridging two network connections. This can be either an Ethernet port and a Wi-Fi® connection, or two Ethernet jacks. If one Ethernet port is bridged to another and one is plugged in to a modem, then the other may be connected to a second computer, providing it with Internet access as well.