> ## Documentation Index
> Fetch the complete documentation index at: https://docs.abbyy.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Architecture
> Explore the multi-layered client-server architecture of ABBYY FlexiCapture: Application, Processing, and Licensing servers, Database, FileStorage, and clients.
ABBYY FlexiCapture has a multi-layered client-server architecture.
## Server side
The server side has three layers:
### Application layer
* **Application Server** — a web service in Internet Information Services (IIS) that acts as the main gateway for HTTP/HTTPS traffic. It verifies user authentication and authorization and runs the FlexiCapture business logic.
* **Licensing Server** — a service that manages FlexiCapture licenses and tracks license usage across all connected clients.
### Processing layer
* **Processing Server** — a service that manages a pool of Processing Stations for distributed computing.
### Data storage layer
* **Database** — a repository of processing settings, personal user data, and statistics on processed documents and documents in progress.
* **FileStorage** — a store of document images and data.
Each of these components can be installed on a separate computer for customizable security, reliability, and independent scaling.
## Client side
* **Scanning Stations and Verification Stations** — capture document images, feed them to FlexiCapture, and verify the extracted data. They are available as:
* Local clients
* Web clients that run in a browser
* Mobile applications
* **Processing Stations** — import and process images, perform optical character recognition (OCR), run custom scripts, export captured data to the customer’s ERP system, and perform various service operations.
* **Administration and Monitoring Web Console** — administers the system and monitors document processing.
* **Project Setup Station** — configures document and data processing settings.
The following diagram shows how these components fit together:
