Glossary

What is an operating system?

An operating system is the foundational software that manages a device's hardware and provides the platform on which applications run — iOS, Android, Windows, macOS.

Engineering and integration

All 220 terms

Why the OS matters to advertising

Because it sets the rules, and it can change them unilaterally.

The operating system decides what identifiers exist, what permissions are required, what data an application may access, and what measurement is possible. Every advertising capability on a device exists at the operating system's discretion.

That has made OS policy the single largest force reshaping digital advertising over the past five years — larger than any regulation, any platform change, or any shift in consumer behaviour.

What OS decisions have changed

[ATT](/resources/glossary/app-tracking-transparency-att) gated the advertising identifier behind an explicit prompt, ending deterministic mobile attribution for most iOS users.
[SKAdNetwork](/resources/glossary/skadnetwork-skan) and [AdAttributionKit](/resources/glossary/adattributionkit) replaced it with aggregated, delayed reporting.
[Privacy Sandbox on Android](/resources/glossary/privacy-sandbox-on-android) is moving the same direction with a replacement-first approach.
[Privacy manifests](/resources/glossary/privacy-manifests) made SDK data collection declarable and inspectable.
Store policy determines what is permissible to build at all.

The strategic implication

Any capability that depends on operating system permission is temporary. This is not pessimism; it is the observable pattern of the last decade, and every measurement approach that assumed otherwise has been broken by a release note.

The capabilities that have proven durable are the ones that need no permission: first-party data from your own users, contextual signals, and causal measurement that never depended on identifying anyone.

It is worth noting that conversational advertising sits on that durable side by construction. Targeting against what a user has just said requires no device identifier, no cross-app tracking and no OS permission — which makes it structurally insulated from the force that has disrupted everything else.

Common questions

Will Android follow iOS on tracking restrictions?

It is moving the same direction on a longer timeline, building replacement APIs before removing capability. Planning as though the identifier is temporary is the safe assumption on both platforms.

Can regulation force platforms to allow tracking?

Regulatory attention has focused mainly on competitive fairness — whether platforms restrict others while exempting themselves — rather than on requiring tracking to be permitted.

More in engineering and integration

The interfaces and plumbing an ad stack is wired together with.

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