DSL - Digital Subscriber Line
DSL is one of the most prevalent forms of Internet connection. DSL provides high-speed networking over ordinary phone lines using digital modems. DSL connection sharing can be easily achieved with either wired or wireless broadband routers. DSL service is also known as ADSL, ADSL2 or ADSL2+.
Cable - Cable Modem Internet
Like DSL, cable modem is a form of broadband Internet connection. Cable Internet uses neighborhood cable television conduits rather than telephone lines, but the same broadband routers that share DSL Internet connections also work with cable.
Dial Up Internet
Once the world standard for Internet network connections, dial up is slowly being replaced with higher-speed options. Dial up uses ordinary telephone lines but, unlike DSL, dial up connections take over the wire, preventing simultaneous voice calls.
Dial up is most commonly utilized in lightly populated areas where cable and DSL Internet services are unavailable.
ISDN - Integrated Services Digital Network
In the 1990s, ISDN Internet served many customers wanting DSL-like service before DSL became widely available. ISDN works over telephone lines and like DSL, supports simultaneous voice and data traffic. Additionally, ISDN provides 2 to 3 times the performance of most dial up connections. Home networking with ISDN works similarly to networking with dial up.
Enterprises like Starband, Direcway and Wildblue offer satellite Internet service. With an exterior-mounted mini-dish and a proprietary digital modem inside the home, Internet connections can be established over a satellite link similar to satellite television services.
Satellite Internet can be particularly troublesome to network. Satellite modems may not work with broadband routers, and some online services like VPN and online games may not function over satellite connections.
BPL - Broadband over Power Line
BPL supports Internet connections over residential power lines. The technology behind power line BPL works analogously to phone line DSL, using unused signaling space on the wire to transmit the Internet traffic. However, BPL is a controversial Internet connection method. BPL signals generate significant interference in the vicinity of power lines, affecting other licensed radio transmissions. BPL requires specialized (but not expensive) equipment to join to a home network.
Do not confuse BPL with so-called powerline home networking. Powerline networking establishes a local computer network within the home but does not reach to the Internet. BPL on the other hand, reaches to the Internet Service Provider over utility power lines.
Other Forms of Internet Connectivity
In fact, several other types of Internet connections have not yet been mentioned. Below is a short summary of the last remaining options:
Fractional T1/T3 Internet - T1 and T3 are the names telecommunications firms have given to leased line network cables. Installed in some multi-resident dwellings, fractional T1/T3 lines are typically underground fiber or copper cables that connect directly to the service provider, with individual home connections switched over Ethernet cables.
Cellular Internet - Mobile Internet connections can be made over digital cell phones. Due to high cost, cellular Internet will only be used in homes during emergencies.
Wireless Broadband Internet - WiMax technology supports high-speed wireless Internet via base stations like cellular networks. So-called WiFi community or "mesh" networks serve a similar function using different technologies.