A Knowledge Box is a container for your data.
A resource is a record in a Knowledge Box.
A field is a value stored in a resource. A value can be a file, a text, a web page, or a conversation.
In many cases, a resource contains only one field (typically, if you upload a PDF file to your Knowledge Box from the dashboard, it will create a resource containing one unique file field).
But it is possible to store multiple fields in a resource, for example, imagine you want to manage cooking recipes in your Knowledge Box, each resource could contain: an image showing the dish, a text explaining the recipe, a video showing the preparation, and a conversation containing people's comments. All of theses different elements would be fields in the same resource.
After extracting all the text content from each field of a resource, Nuclia split it into text blocks. These text blocks are not related to any text layout from the original document. They are just the atomic piece of meaning that Nuclia will index.
When processing the text, Nuclia identifies all the key concepts (like people names, locations, dates, financial amounts, …). These concepts are named entities. They are stored as metadata in the resources. They can be used for filtering.
Nuclia also builds a knowledge graph representing the relations between entities and resources.
You can define some sets of labels that can be assigned to either resources, either text blocks. It can be used for filtering, or for trainings.
API keys / NUA keys
An API key allows to make authorized API calls to a Knowledge Box.
NUA keys (standing for "Nuclia Understanding API") are not related to a Knowledge Box but to the entire account, they allows to trigger processing tasks.