Ποια είναι η διαφορά μεταξύ ενός διακομιστή ιστού και μιας υπηρεσίας ιστού;

A web server is a program that receives HTTP/HTTPS requests from clients (browsers) and responds with web pages, images, videos, and other files.

A web service is a collection of technologies for exchanging data between applications over a network. It does not necessarily return web pages and often uses formats like XML, JSON, or message transmission protocols (e.g., SOAP, REST).

// Example of a minimal web server in Node.js
const http = require('http');

const server = http.createServer((req, res) => {
  res.statusCode = 200;
  res.setHeader('Content-Type', 'text/plain');
  res.end('Hello World\n');
});

server.listen(3000, () => {
  console.log(`Server running at http://localhost:3000/`);
});

# Example of a simple web service (REST API) in Python using Flask
from flask import Flask, jsonify, request

app = Flask(__name__)

@app.route('/api/data', methods=['GET'])
def get_data():
    # Return data in JSON format
    return jsonify({'message': 'This is some data'})

if __name__ == '__main__':
    app.run(debug=True)

Characteristic	Web server	Web service
Main purpose	Serving static and dynamic web pages for browsers	Providing programmable functions for other applications
Data format	HTML, CSS, JavaScript, images, videos, etc.	XML, JSON, SOAP, messages, etc.
Protocols	Mainly HTTP/HTTPS	HTTP/HTTPS, SOAP, REST
Consumer	Web browsers (humans)	Applications, other web services (machine)
Connection with web service	Can run or host web services	Can be part of or use a web server