✅ Mutable can be modified after initialization encapsulate: getter, setter, private, final field need to synchronize access for multi thread String Builder Stirng Buffer java.util.D...

✅ Garbage Collection? Garbage collection When Java is run on JVM, manage heap Stop the world, major GC 💡 https://soheeparklee.github.io/posts/JAVA_JVM/#%EF%B8%8F-garbage-collect...

✅ MVC Model / View / Controller 소프트웨어 설계 패턴 중 하나 앱을 모델, 사용자 인터페이스, 비즈니스 로직으로 구분하여 개발 ✅ MVC Design Pattern ✔️ Model business logic database respond to request for information fro...

✅ UI User Interface web design, layout font, color, space reactive, animation ✅ UX User Experience analyse experience with the page, make the web more comfortable and effici...

✅ Logging use log4j use different levels to express urgency of error ✅ ERROR Immediate solution required for program running ✅ WARN Need to be warned, but program is running unabl...

✅ API key User issues API key To use certain API, send key with request When requested, Application authenticated user information with key Respond to user with information from key ...

✅ OAUTH Open Authoization Authentication from a trusted organization, without the user having to signup, login for your company Share account information from google, kakako ✅ OAUTH pr...

✅ 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 sta...

✅ Static Page page written in HTML, CSS, JS when server revcieves request, send response to client ✅ Dynamic Page pages writeen in CGI, AJAX, ASP, ASP.NET, etc content of pages is diff...

✅ Main components of the broswer browser follows HTML and CSS rules based on W3C world wide web consortium Each tab runs in a seperate process(multiple instances of rendering engine) 1. U...