EWD Components

=== EWD Components The following is a functional description of the moving parts of EWD so the user/developer has a good idea of how the parts fit together and how they work or don't work. I will describe the variant which is Open Source and specifically the back end GTM and front end JavaScript and mainly custom tag sets invoking extJS Framework and Sencha Touch for touch-based smart phones and tablet devices. Other variants are available in the full MGateway products, but are ignored for simplicity here.

An EWD system consists of a server system accessed by browser clients.

The Server may run Apache or a Node-js Server (or both to be strictly correct).  As such it must have a domain-name or IP address on the LAN or the Internet.

Usually an EWD-based system will operate securely using https:// protocol and therefore use SSH as a component of the server.  See details of how it uses port 443 typically to encrypt messages transmitted between client browser and server over what my be the public Internet or a private (hospital) Intranet (LAN - local area network plus or minus wireless linkages. See EWD Network and SSH.

An Apache web server can be a complex topic in itself because of the multitude of features and modes available in this amazing open source product.  Once configured, however, it just works and need not worry the developer after a system is set up and configured.  Getting there is managed in the dEWDrop Virtual Machine or by AstroVistA debian-type installer.