ATM vs. leased line?

What is the difference between a leased line and ATM?
Answer: The major difference between the two is that ATM is a technology and leased lines are data lines at varying speeds, depending on need and cost, leased from a provider. ATM is a switching technology that packages all information into packets called octets. All of this information, regardless of whether it?s data, voice, video, etc. is broken into these octets and transferred across the network. ATM networks can be comprised of many different media, such as fiber internally and leased lines (T-1, T-3, etc) externally.