Glossary

Definitions of terms used throughout Big Picture documentation.

Release Management

Release

An immutable version of a product published to a channel. A release includes version metadata, artifact references, and signing information. Once published, a release cannot be modified—only revoked.

Channel

A named stream of releases (e.g., stable, beta, internal). Clients subscribe to channels and receive update decisions based on releases in that channel.

Artifact

An installer or package file (MSI, MSIX, ZIP, etc.) that contains the software to be installed. Artifacts are stored in artifact repositories and referenced by releases.

Update Decision

A signed response from Big Picture indicating what action a client should take:

• NONE: Take no action
• NOTIFY: Notify user but don’t install
• DOWNLOAD: Download but don’t install
• INSTALL: Install automatically

Policy

Rules that govern update behavior, including update modes, version pinning, blocklists, and staged rollout percentages. Policy can be set globally, per-tenant, or per-product.

Staged Rollout

Gradually releasing a new version to a percentage of clients, enabling canary deployments and risk mitigation.

Revocation

Marking a release as revoked, preventing new clients from receiving it while existing installations remain unchanged.

Licensing

Entitlement

A customer’s right to use software, defined by products, license type, validity period, and features. Entitlements are the source of truth for licensing decisions.

License Lease

A short-lived, signed token granting temporary permission to use software. Leases expire after a configurable duration and must be renewed periodically.

License Server

A service that evaluates entitlements and issues license leases. Can be cloud-hosted or locally deployed.

Per-User Licensing

A license model where each licensed user can activate software on any machine. The license server tracks active users and enforces seat limits.

Per-Machine Licensing

A license model where each licensed machine can run software regardless of user. The license server tracks machine identities and enforces device limits.

Floating (Concurrent) Licensing

A license model where a pool of licenses can be used by any user or machine up to the concurrent limit. Licenses are checked out when in use and checked in when released.

Seat Assignment

The assignment of a license seat to a specific subject (user, machine, or device). Used when seat_assignment_mode: "explicit" is set in the entitlement policy.

Seat Assignment Mode

Determines how seats are managed:

• automatic: Seats are tracked automatically through active leases (default)
• explicit: Seats must be explicitly assigned before users can request leases

Deployment and Infrastructure

Tenant

An organizational boundary in Big Picture. Tenants have isolated catalogs, policies, and entitlements. In SaaS deployments, each customer is a tenant.

Mirror

A downstream service that pulls signed snapshot bundles from Big Picture and serves artifacts locally. Enables self-hosting for regulated environments.

Snapshot

An immutable, signed bundle containing complete catalog state at a point in time. Mirrors pull snapshots to replicate Big Picture’s catalog locally.

Artifact Repository

External storage for installers (JFrog, S3, GCS, etc.). Big Picture references artifacts in repositories but doesn’t store them directly (unless using managed storage).

Managed Storage

Optional Big Picture-managed artifact storage. When enabled, Big Picture stores artifacts directly rather than referencing external repositories.

Security and Trust

Signature

A cryptographic signature (Ed25519) attached to update decisions, license leases, and snapshots. Clients verify signatures before trusting data.

Signing Key

The private key used to sign authoritative data. Stored in HSM or KMS and never exposed to clients.

Public Key

The public portion of a signing key pair. Clients pin public keys and use them to verify signatures.

Trust Boundary

A conceptual boundary between trusted and untrusted components. Big Picture defines trust boundaries at clients, networks, and services.

Operational Concepts

Update Check

A client request to Big Picture asking what action should be taken. Big Picture evaluates policy and returns a signed update decision.

Lease Renewal

A client request to extend an expiring license lease. License servers evaluate entitlements and issue new leases.

Audit Log

An append-only log of all significant events: releases published, policies changed, leases issued, decisions made. Supports compliance and incident response.

Kill Switch

A global or per-tenant mechanism to immediately stop all updates or license issuance. Used for incident response.

API Concepts

OAuth2 Scope

A permission identifier that defines what operations an access token can perform. Examples: ci:write, artifacts:write, admin:read.

Service Account

A non-user account used for programmatic API access, typically for CI/CD pipelines and automation.

Subject

An entity that can request license leases. Types include: user, machine, device.

Subject ID

A unique identifier for a subject within a tenant context.