# The stack (philosophy)

"The stack" is a term used in science and technology studies, the philosophy of technology and media studies to describe the multiple interconnected layers that computation depends on at a planetary scale. The term was introduced by Benjamin H. Bratton in a 2014 essay and expanded upon in his 2016 book The Stack: On Software and Sovereignty, and has been adapted, critiqued and expanded upon by numerous other scholars.

## Use in scholarship

The stack refers to the entire global megastructure of interconnected computer systems. The stack includes not only technology and software, but also depends on human users, natural resources and corporate infrastructures.
The term draws upon the concept of the stack in programming and by the layered architecture of the Internet Protocol, but provides a model at a planetary scale.
In an essay that is critical of Bratton's model, Geert Lovink proposes instead of referring to a singular stack we should speak of "a rainbow of a thousand stacks", such as Tiziana Terranova's "red stack" or the "green stack" aiming to reduce the extreme energy use of blockchain and data centres.

## Stacks and layers

Different scholars have proposed different layers that make up the stack as they understand it. The layers often depend on what the scholar wants to research, whether it is a specific cultural context, such as the Chinese or European internet, or a specific technology, as artificial intelligence or self-driving cars. The term has also been used to describe a model for ensuring diversity in the digital humanities.

### Bratton's six layers

Bratton proposed six interconnected layers: earth, cloud, city, address, interface and the user.
* Earth: Computing requires materials mined from the earth and energy that is often generated by oil or coal, and they produce electronic waste. This layer provides the building blocks of the global digital stack.
* Cloud: Global, usually corporate technology services like Google, which have a type of power Bogost calls a "weird sovereignty".
* City: The lived experience of physically interacting with the global computer network in daily life, often discussed in relation to smart cities.
* Address: Identification of individual users and objects and its use for management and control.
* Interface: How users are connected to computers and systems.
* The user: The actual humans (and nonhumans) that interact with computers and computational systems.

### Layers in "the Chinese stack"

Gabriele de Seta has proposed three additional layers that are needed to understand what he calls "the Chinese stack", which is not delimited to the borders of China but is entwined with planetary networks. These layers maintain the focus on planetary computing and the internet as a global system, but support analysis of the connections - and lack of connections - between parts of the internet, and how this relates to power.
* Gateways: interfaces between systems allowing different types of data to be connected. QR codes are an example.
* Sieves: filters, blacklists, verification systems and regulations that provide access to parts of the internet to some users.
* Domes: enclosures that aim to control parts of the internet by shutting off access to the rest of the stack.

### Other layers

In an article on European digital sovereignty, Haroon Sheikh uses layers inspired by but not identical to Bratton's: the resource layer, the chips layer, the network layer, the cloud layer, the intelligence layer, the applications layer and the connected device layer. Sheikh describes Bratton's layers as coming from a "more speculative philosophical approach", while his analysis is more pragmatic in that it aims to understand the digital capacities of the EU and therefore follows industry distinctions and leaves out users, while keeping the basic idea of a layered stack.

## Governance and power

The layered framework of the stack is often used to analyse how power, control and governance are enacted globally through technology. The stack has been used in the fields of economics and business to explain the connections between technology and global capitalism.
Bratton discusses how sovereignty changes with global structures like the stack, with a shift from territorial or national sovereignty, where a geographically defined nation rules itself, to a system where a global corporation like Google can operate as a global sovereign. This builds on Michel Foucault's theories of governmentality and power, and Bratton's book has been described as possible to read as "a Foucaudian toolkit that lifts out the useful parts".

## Criticism

Although Bratton's book has been criticised as overly long and complex, the term the stack is now commonly used in scholarship on the internet. In his critical essay "Stacktivism" (a reference to the pejorative term slacktivism) Geert Lovink describes the book as a "media theory classic" that is "inspiring to disagree with." Lovink further argues that the term "the stack" has become a "general container concept, in danger of becoming an empty signifier".