지식 수준 맞추기

• Node.js is a programming language?

  : No. It's a flatform which can be executed JS without browser

• npm is the same program with Node.js?

  : No. npm is Node Package Manager.

• express is a server?

  : No. We make server with express. This library helps making web server.

Understanding about Web site, Web browser and technique

• HTTP: HyperText T Protocol. Everyone's promise when request and response data.
• Web Browser: Response HTML data and draw it to screen.
• Cookie 🍪: Using when saving states. w/o encrypting. not safe but light
• Session 🔐: technique with cookie. w encrypting. Client gets key. safe but heavy

Express (Library)

• helps making server
• Using middleware technique
• Can serve Static files with my server to client