http://earlybird.kr/1584http://hyunalee.tistory.com/4 1. session, cookie, token2. spring security filter 종류 https://yongdev.tistory.com/139 OAuth 2.0 인증 방식 https://cheese10yun.github.io/oauth2/https://okky.kr/article/420615 1. Authorization Code Grant Type : 권한 부여 코드 승인 타입2. Implicit Grant Type : 암시적 승인3. Resource Owner Password Credentials Grant Type4. Client Credential Grant Type