Fiber-optic is the fastest and most reliable form of internet, but it can be more expensive and is not available everywhere in the USA. It transmits data via light signals in glass fibers. Cable is slower than fiber but still very fast. It uses coaxial cables to transmit data, like your television. DSL is slower than cable and fiber, but the infrastructure supporting it exists throughout the country because it uses traditional phone lines. Satellite internet can beam a signal to pretty much any location where a satellite dish is installed.