A web server is a computer that stores information, modifies it, and provides clients with access to it. These clients can request information or ask the server to process data in a specific way, which can result in a change to the data stored on the server and the client receiving a representation of this data. Practically, any computer can be a web server. A web app is a process that runs on a web server and serves content to clients through HTTP requests. In production environments, web apps run on specially configured web servers, which provide redundancy, replication, and other features to ensure robustness, high performance, and safety, among other characteristics. However, you do not need a fully fledged web server to run a web app. You can run a web app on your development computer.
An order management server is a web app that runs on a computer that is accessible to clients. In your development environment (which is comprised of your...