Are you asking what its actual purpose is in the overall scheme of things?

Yes, please

Here's the official description from Sage.

Web presentation server The Web presentation server is a front-end server that end users access to open a Sage X3 session through their internet browsers. During installation, especially in documents and screens, Web presentation server can also be referred to as Syracuse.

It works in asynchronous mode based on the Node.js software platform, which contains a built-in HTTP server library which is used to provide a web publication server. Each X3 function has its own URL and sends normalized (SData) Java Script feeds in JSON format to the client (web browser on user’s workstation or web services client). Operating data, such as Windows customization, dashboard, endpoints, management roles, user information, and electronic documents that users can register via their storage area, are stored in a documentoriented MongoDB database.

The Syracuse Web Server can be clustered to ensure scalability when a high number of concurrent interactive connections and/or web services are needed. This Syracuse Web Server also manages: • Workflow links • Incoming and outgoing SOAP and REST Web Service

Here's the official description from Sage.

Web presentation server The Web presentation server is a front-end server that end users access to open a Sage X3 session through their internet browsers. During installation, especially in documents and screens, Web presentation server can also be referred to as Syracuse.

It works in asynchronous mode based on the Node.js software platform, which contains a built-in HTTP server library which is used to provide a web publication server. Each X3 function has its own URL and sends normalized (SData) Java Script feeds in JSON format to the client (web browser on user’s workstation or web services client). Operating data, such as Windows customization, dashboard, endpoints, management roles, user information, and electronic documents that users can register via their storage area, are stored in a documentoriented MongoDB database.

The Syracuse Web Server can be clustered to ensure scalability when a high number of concurrent interactive connections and/or web services are needed. This Syracuse Web Server also manages: • Workflow links • Incoming and outgoing SOAP and REST Web Service

https://partnerportal.sagex3.com/sites/default/files/sage_x3_partner/storage/architecture_guide_v11.pdf

Thanks.