Web Server/ WAS

✅ Web Server

hardware: computer where web server is installed
software: recieve HTTP request from client, response static page

• based on HTTP protocol
• when client request, provide static content

• send request for dynamic page to WAS

• provive static page

• static page

  • HTML
  • CSS
  • image
  • file
  • contents that immediate response is possible
• Apache
• Nginx
• IIS

✅ WAS

Web Application Server
Web server ➕ web container
🟰 sevlet container
provide dynamic pages that require DB searching, logics

• based on HTTP protocol

• container: software that can run JSP, servlet

• connect to DB
• for dynamic pages

• more focused on DB, logics

• JSP
• Servlet
• Tomcat
• JBoss

Web server 🆚 WAS

❓ why divide Web server and WAS?

• web server: simpler static page
  
• WAS: more complex DB connection, logics, dynamic page
  

❓ Why not use just WAS for static pages as well?

WAS can provide static pages as well
However, use web servers as well because…

1. Prevent server overflow

• divide WAS and web server to prevent server overflow
• WAS: DB search, logic
• web server: simple static page
• If WAS also has to provide static pages, more overflow

2. Security

• use web server for SSL encrpytion

3. Several WAS

• can connect to several WAS
• and use web server for load balancing
• provide availability

4. Several web application services

• can use PHP, JAVA application in one server