This page aims at explaining the logic of the **Catalogues Sets** configured in the Test Suite and used in many Test Scenarios.

## Common Baseline Sets

The Common Baseline Sets are **global collection definition** that are used in [TS01](Test-Scenarios-Description#ts01), [TS02](Test-Scenarios-Description#ts02), [TS04](Test-Scenarios-Description#ts04), [TS05](Test-Scenarios-Description#ts05) and [TS06](Test-Scenarios-Description#ts06).
They are used in the following test strategies:

* [Catalogue Filters Randomization (TS01 & TS02)](Test-Scenarios-Description#catalogue-filters-randomization-ts01--ts02)
* [Offline Download (TS04)](Test-Scenarios-Description#offline-download-strategy-ts04)
* [Data Coverage Benchmark (TS05)](Test-Scenarios-Description#data-coverage-benchmark-strategy-ts05)
* [Data Coverage Benchmark (TS06)](Test-Scenarios-Description#data-latency-benchmark-strategy-ts06)

In this guide we often use the term **Copernicus Product Types** that actually are the collections defined under the set key `Copernicus` (see [data node configuration](Configure-The-Test-Suite#data-node))

## Target Site Sets

The Target Site Sets are the data collection specific to each Target Site. There are classified in 2 categories:

* [Baseline](#target-site-baseline-sets)
* [Local](#target-site-local-sets)

### Target Site Baseline Sets

The Baseline Sets are linked to a [Common Baseline Set](#common-baseline-sets) to define the data collections of the Target Site in respect of the baseline sets. For instance, in the default configuration, a [Common Baseline Set](#common-baseline-sets) called `Copernicus` is configured with most of the product types of the Copernicus programme. To perform a proper benchmark of the Copernicus data access service of all the configured target sites, they must all reference this `Copernicus` set as a baseline.

Nevertheless, the referenced set can be amended with a set of parameters specific to the Target Site to fit with the baseline. For instance, if the Target Site catalogue contains products that are not part of the Copernicus baseline, a specific parameter such as `processingCenter` would reference the `ESA` ground segment data origin.

### Target Site Local Sets

The Local Sets define the data collections specifically defined as locally managed by the Target Site. In other words, those sets represent the "Online data offer" of the service provider. It is used in the Test Case [TC503](Test-Scenarios-Description#tc503).

## Comparative Catalogues Function

The Comparative Catalogues Function is the methodology used is the Test Cases [TC50X](Test-Scenarios-Description#tc501) & [TC60X](Test-Scenarios-Description#tc601) to compare data collections from a Target Site to the Reference Site defined in the [catalogue configuration](Configure-The-Test-Suite#service_providersnamedatacatalogue-node) of the Target Site.
The Test Cases needs a reference to measure the metrics such as data coverage or publication latency. They are calculated by comnparing the data collection information (e.g. total number of items in the catalogue, publication date) of the Target Site versus the Reference Site.
For a proper benchmarh, this reference site must be the same for all Target Sites.