A technology stack comprises the layers of components or services that are used to provide a software solution or application. Traditional examples include the OSI seven-layer model

OSI model

The Open Systems Interconnection model is a product of the Open Systems Interconnection effort at the International Organization for Standardization. It is a prescription of characterizing and standardizing the functions of a communications system in terms of abstraction layers. Similar...

, the TCP/IP model, and the W3C technology stack.

Technology stacks are often articulated as a list of technologies, such as "J2EE with Java Server Faces running against a SQL Server database" or as a diagram.