Definitions and terminology

In any multidisciplinary field, definitions and terminology have a tendency to create trip-hazards. This is definitely the case in “platform land”. A service may mean something different to a service designer than it does to a software engineer; for some a platform carries with it assumptions about multi-sided market places, for others, it’s just a component to be built upon.

In this playbook, the following definitions are used:


Public-facing services allow citizens or their representatives to achieve a desired outcome. With appropriate governance, services can be provided by any layer of government, and by commercial or third sector organizations. Services are the things that are built on top of platforms.

Digital proofs

The term digital proofs is used to cover the various different ways that someone can prove a fact (for example that they are entitled to a free prescription). This includes cryptographically signed data, and one-use codes or barcodes that can be used to verify a fact online.

Government as a Platform

The term ‘Government as a Platform’ is used to refer to the whole ecosystem of shared APIs and components, open-standards and canonical datasets, as well as the services built on top of them and governance processes that (hopefully) keep the wider system safe and accountable.

Shared APIs

Shared APIs expose the business logic of government, for example, calculating a benefit payment or checking the status of an application. They are referred to as “shared” to indicate that they are available for use beyond the agency that developed them.


The term platform is used in the generic sense to refer to any shared API, shared component, trust and identity system, or register.


Registers are canonical datasets that are used and trusted across government and beyond. For example, a single list of postal addresses or a single list of registered companies. They expose the data via APIs to agreed open-standards and have appropriate governance and ownership in place.

Shared components

Shared components solve common problems for the whole of government (and potentially beyond). For example: sending a text message, hosting a web application, taking a payment or signing a document.

Trust and identity systems

Trust and identity systems ensure that data is only accessed for appropriate purposes, and that use is understandable and trusted by citizens or their representatives. For example: authentication, trust verification, data exchange and key management systems.