Provide concept guide for the Kanto File Upload

- Provide information about what is a File Upload and how it works
- Provide an illustration of this concept

Signed-off-by: Antonia Trifonova [email protected]

web/site/content/docs/concepts/file-upload.md

@@ -0,0 +1,24 @@
+---
+title: "File upload"
+type: docs
+description: >
+  Empower the edge device to upload data to various storage providers.
+weight: 4
+---
+
+File upload enables sending of files to a backend storage of choice. It can be used both locally and remotely via a desired IoT cloud ecosystem. The following use cases are provided:
+
+* **Storage diversity** - with ready to use integrations with Azure Blob Storage, Amazon S3 and standard HTTP upload
+* **Automatic uploads** - with periodically triggered uploads at a specified interval in a given time frame
+* **Data integrity** - with an option to calculate and send the integrity check required information
+* **Operation monitoring** - with a status reporting of the upload operation
+
+![File upload](/kanto/images/docs/concepts/file-upload.png)
+
+## How it works
+
+It's not always possible to inline all the data into exchanged messages. For example, large log files or large diagnostic files cannot be sent as a telemetry message. In such scenarios, file upload can assist enabling massive amount of data to be stored to the backend storage.
+
+There are different triggers which can initiate the upload operation: periodic or explicit. Once initiated, the request will be sent to the IoT cloud for confirmation or cancellation transferred back to the edge. If starting is confirmed, the files 
+to upload will be selected according to the specified configuration, their integrity check information can be calculated and the transfer of the binary content will begin. A status report is announced on each step of the upload process 
+enabling its transparent monitoring.