Glossary

A flat lookup of terms used in the portal and in this documentation. For the AGO term ↔ GratisGIS term mapping, see Terminology map under Coming from ArcGIS Online.

A

Admin. The role with full org control: user management, org settings, housekeeping, backups, geocoders.

ArcGIS service. Item type wrapping a reference to an external ArcGIS REST feature service or map service. Read-only proxy.

As of (time slider). A control in the map editor (and attribute table) that shows the layer as it existed at a past point in time. Powered by the engine's observation log.

Attachment. A file (typically a photo) bound to a specific feature on a data layer. Stored in MinIO; the metadata row lives in the feature_attachment table.

B

Basemap. Item type wrapping a single base-layer reference (style URL, tile URL, WMS, or portal map). Every map picks one.

Bitemporal. Stored with two time dimensions: when an event happened in the world and when the system observed it. The engine's observation log is bitemporal.

Bundle export. A .zip archive containing a layer's XLSX, related-table rows, and attachments. The "give me the whole thing" export option.

C

Calculate step. A derived-layer step that adds a computed column. Same expression dialect as filters.

Class breaks. A graduated-symbology mode where the value range is divided into N classes, each rendered with its own color or size.

Cluster. A run-time grouping of nearby point features into a single rendered point. Configurable per map layer.

Contributor. A role that can publish items (data layers, maps, forms, web apps). Formerly "publisher" in AGO vocabulary.

D

Data layer. The native item type for feature data, owned by the portal. One or more PostGIS-backed sublayers. The native equivalent of an AGO feature service.

Dependency. A reference from one item to another. The portal tracks dependencies in both directions so you can see what a map references and what references a map.

Derived layer. Item type whose features are the materialized result of an analysis pipeline. Lives in its own PostGIS table.

E

Engine. The observation-log substrate underneath data layers. Records every edit as an event; reads project the events into the current state. Mostly invisible day-to-day.

F

Feature. A single row in a layer. Has a geometry, attributes, and (optionally) attachments.

Feature service (AGO term). Maps onto data layer in GratisGIS. See Terminology map.

Filter (map). A per-map-layer condition that limits which features render on that map. Doesn't alter the underlying layer.

Folder. Item type that groups other items by id. Items can live in many folders simultaneously.

Form. Item type that collects responses from users. Bound to a data layer (for spatial responses) or form submission collection (non-spatial).

Form submission collection. Item type that backs a non- spatial form. Holds responses with no geometry column.

G

Geo boundary. Item type wrapping a reusable polygon referenced by share limits, viewports, dashboard filters, clip steps.

Group by step. A derived-layer step that rolls up rows by key fields and computes aggregates per group.

H

Housekeeping. The admin dashboard that surfaces stale items, quiet users, and broken dependencies with bulk-action affordances.

I

Item. Any addressable thing in the portal. Maps, data layers, forms, web apps, dashboards, files, geo boundaries, basemaps, tile layers, ... all items.

L

Layer. A map layer reference. The map's per-layer style, filter, popup config sits on the reference, not on the underlying data layer.

Layer package. Item type wrapping an archive of a data layer's schema + symbology + features for portable sharing.

M

Map. Item type composing layers, basemap, viewport for viewing or web-app rendering. Formerly "web map" in AGO vocabulary.

O

Observation. A single recorded event in the engine's log ("user U created feature F at time T", "user U set field X to Y on feature F at time T"). Every edit is an observation.

Organization. The multi-tenant boundary. Every item and every user belongs to one org. Cross-org reads are blocked by default.

P

Pick list. Item type wrapping a reusable list of coded values plus labels. Schema fields can reference a pick list.

PMTiles. The single-file tile container format used at rest by Tile layer items. Range-readable over HTTP, no server compute.

R

Report template. Item type wrapping a parametrized document layout that produces a populated PDF or DOCX on run.

S

Share geo limit. A per-share polygon clip on a layer. Restricts what the share's grantee can see to features inside the polygon.

Sharing. The per-item access control. Three tiers (Owner only, Organization, Public) plus optional per-user / per-group shares.

Sublayer. One of the (potentially many) PostGIS-backed tables inside a data layer. Each sublayer has its own schema and geometry type.

T

Tile layer. Item type wrapping a pre-rendered tile container (PMTiles) uploaded to MinIO.

Tool. Item type wrapping a reusable analysis operation with a declared signature. Runs on demand against caller-supplied inputs.

V

Viewport. A map's default center, zoom, bearing, pitch. Can also include a bound geo-boundary so the default view follows the polygon over time.

W

Web app. Item type wrapping a standalone web page (map + widgets) reachable at a URL. Template-driven.

Widget package. Item type wrapping an archive of a custom Web App widget for installation.

WMS. The OGC Web Map Service protocol. GratisGIS supports WMS as a basemap source kind.