Asynchronous transfer mode (ATM) is a technology, which was emerged during the development of broadband ISDN in the 1970s and 1980s. It is an development of packet switching. Like packet switching for data (e.g., X.25, frame relay, transmission control protocol [TCP]/Internet protocol blends the multiplexing and switching functions, is appropriate for busty traffic, in contrast to circuit switching, and permits communications between devices that function at different speeds. Unlike packet switching, ATM architects for high-performance multimedia network. ATM technology has been implemented in a medley of networking devices, such as PC, workstation, and server network interface cards, switched-Ethernet and token-ring workgroup hubs, workgroup and campus ATM switches, ATM enterprise network switches, ATM multiplexes, ATM–edge switches and ATM–backbone switches

ATM can also be offered as an end-user service by providers or as a networking infrastructure.  In ATM networks, all information is formatted into fixed-length cells consisting of 48 bytes (8 bits per byte) of payload and 5 bytes of cell header.
ATM standards have defined two types of ATM connections: virtual path (VPCs), which contains virtual channel connections (VCCs). A virtual path connection can be created from end-to-end across an ATM network. ATM offers a lot of benefits such as high performance via hardware switching, dynamic bandwidth for busty traffic, class-of-service support for multimedia, scalability in speed and network size, LAN/WAN architecture and opportunities for simplification via VC architecture.
 

The application of ATM technologies, standards, and services can be described briefly as below:

• ATM services
• ATM workgroup and campus networks
• Workgroup ATM is more of a niche market with the wide acceptance of switched-Ethernet desktop technologies.
• ATM enterprise network consolidation
• ATM enterprise network switch.
• A full-featured ATM ENS offers a broad range of in-building (e.g., voice, video, LAN, and ATM) and wide-area interfaces (e.g., leased line, circuit switched, frame relay, and ATM at narrow band and broadband speeds) and supports ATM switching, voice networking, frame-relay SVCs, and integrated multi-protocol routing.
• Multimedia virtual private networks and services
• Service providers are making on their ATM networks to offer a broad range of services. Examples include managed ATM, LAN, voice and video services and full-service virtual private-networking capabilities
• Frame-relay service providers are deploying ATM backbones to meet the increasing growth of their frame-relay services to use as a networking infrastructure for a range of data services and to enable frame relay to ATM service inter working services.
• Internet backbones—Internet service providers are assembling ATM backbones to meet the increasing growth of their frame-relay services, to use as a networking infrastructure, a range of data services, and to make possible Internet class-of-service offerings and virtual intranet services.
• Residential broadband networks
• Carrier infrastructures for the telephone and private-line networks