diff --git a/README.md b/README.md
index 395edc5..82642b2 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,3 @@
 # backend-study-sns
+
+강준이
diff --git a/build.gradle b/build.gradle
index 610d6a6..c78d56d 100644
--- a/build.gradle
+++ b/build.gradle
@@ -19,8 +19,16 @@ repositories {
 }
 
 dependencies {
+    // Lombok
+    compileOnly 'org.projectlombok:lombok'
+    annotationProcessor 'org.projectlombok:lombok'
+
 	implementation 'org.springframework.boot:spring-boot-starter-web'
+    implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
+    implementation 'org.springframework.boot:spring-boot-starter-jdbc'
+    implementation 'org.springframework.boot:spring-boot-starter-thymeleaf'
 	testImplementation 'org.springframework.boot:spring-boot-starter-test'
+    runtimeOnly 'com.h2database:h2' // 임시 메모리 DB
 	testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
 }
 
diff --git a/src/main/java/com/example/devSns/controller/PostController.java b/src/main/java/com/example/devSns/controller/PostController.java
new file mode 100644
index 0000000..ae06df7
--- /dev/null
+++ b/src/main/java/com/example/devSns/controller/PostController.java
@@ -0,0 +1,69 @@
+package com.example.devSns.controller;
+
+import com.example.devSns.entity.PostEntity;
+import com.example.devSns.service.PostService;
+import org.springframework.stereotype.Controller;
+import org.springframework.ui.Model;
+import org.springframework.web.bind.annotation.*;
+
+@Controller
+@RequestMapping("/posts")
+public class PostController {
+
+    private final PostService postService;
+
+    // 생성자
+    public PostController(PostService postService) {
+        this.postService = postService;
+    }
+
+    // HTTP GET /posts
+    @GetMapping
+    public String list(Model model) {
+        model.addAttribute("posts", postService.getAllPosts());
+        return "list";
+    }
+
+    // HTTP GET /posts/new
+    @GetMapping("/new")
+    public String form(Model model) {
+        model.addAttribute("post", new PostEntity());
+        return "form";
+    }
+
+    // HTTP POST /posts
+    @PostMapping
+    public String create(@ModelAttribute PostEntity postEntity) {
+        postService.createPost(postEntity);
+        return "redirect:/posts"; // 글 생성 후 돌아올 주소
+    }
+
+    // HTTP GET /posts/{id}
+    @GetMapping("/{id}")
+    public String detail(@PathVariable Long id, Model model) {
+        model.addAttribute("post", postService.getPost(id));
+        return "detail";
+    }
+
+    // HTTP GET /posts/{id}/edit
+    @GetMapping("/{id}/edit")
+    public String editForm(@PathVariable Long id, Model model) {
+        PostEntity postEntity = postService.getPost(id);
+        model.addAttribute("post", postEntity);
+        return "edit";
+    }
+
+    // HTTP POST /posts/{id}/update
+    @PostMapping("/{id}/update")
+    public String update(@PathVariable Long id, @ModelAttribute PostEntity updatedPost) {
+        postService.updatePost(id, updatedPost);
+        return "redirect:/posts/" + id; // 수정 후 돌아올 주소
+    }
+
+    // HTTP POST /posts/{id}/delete
+    @PostMapping("/{id}/delete")
+    public String delete(@PathVariable Long id) {
+        postService.deletePost(id);
+        return "redirect:/posts"; // 삭제 후 돌아올 주소
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/com/example/devSns/controller/explanation b/src/main/java/com/example/devSns/controller/explanation
new file mode 100644
index 0000000..d86130e
--- /dev/null
+++ b/src/main/java/com/example/devSns/controller/explanation
@@ -0,0 +1,24 @@
+요청을 받는 곳
+
+PostController
+Spring MVC 패턴에서 Controller 계층 역할
+- 사용자의 요청을 받고 Service 계층을 호출해서 처리한 후, 결과를 View에 전달
+
+@Controller
+이 클래스는 웹 요청을 처리하는 컨트롤러임을 알려줌
+- Model에 데이터를 담아 템플릿에 전달 (templates/list.html)
+
+@RequestMapping
+클래스 전체의 기본 URL 경로를 지정
+- 이 컨트롤러 안의 모든 요청은 /posts로 시작
+- /posts (게시글 목록), /posts/new (새 글 작성 폼)
+
+@GetMapping, @PostMapping
+HTTP 메서드 별 라우팅
+
+@PathVariable, @ModelAttribute
+URL 경로 변수 바인딩 / 폼 데이터를 객체에 바인딩
+
+@RestController
+문자열 반환이 뷰 이름이 아닌 JSON
+- REST API 만들 때 사용
\ No newline at end of file
diff --git a/src/main/java/com/example/devSns/dto/explanation b/src/main/java/com/example/devSns/dto/explanation
new file mode 100644
index 0000000..095c837
--- /dev/null
+++ b/src/main/java/com/example/devSns/dto/explanation
@@ -0,0 +1,8 @@
+계층간 데이터 교환에 사용
+- Entity 클래스를 보호
+- 필요한 데이터만 선택적으로 담을 수 있음
+
+분리해서 사용하는 이유
+- Entity 객체의 변경을 피하기 위함
+- 클라이언트와 통신하는 ResponseDTO나 RequestDTO는 요구사항에 따라 자주 변경
+- 어떤 요청에서는 특정 값이 추가되거나 없을 수 있어서 분리해서 관리
\ No newline at end of file
diff --git a/src/main/java/com/example/devSns/entity/PostEntity.java b/src/main/java/com/example/devSns/entity/PostEntity.java
new file mode 100644
index 0000000..ccaad1a
--- /dev/null
+++ b/src/main/java/com/example/devSns/entity/PostEntity.java
@@ -0,0 +1,35 @@
+package com.example.devSns.entity;
+
+import jakarta.persistence.*;
+import lombok.Getter;
+import lombok.Setter;
+
+import java.time.LocalDateTime;
+
+@Entity
+@Getter
+@Setter
+public class PostEntity {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    private String title;
+    private String content;
+    private String author;
+
+    private LocalDateTime createdAt;
+    private LocalDateTime updatedAt;
+
+    @PrePersist
+    protected void onCreate() {
+        this.createdAt = LocalDateTime.now();
+        this.updatedAt = LocalDateTime.now();
+    }
+
+    @PreUpdate
+    protected void onUpdated() {
+        this.updatedAt = LocalDateTime.now();
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/com/example/devSns/entity/explanation b/src/main/java/com/example/devSns/entity/explanation
new file mode 100644
index 0000000..402a31e
--- /dev/null
+++ b/src/main/java/com/example/devSns/entity/explanation
@@ -0,0 +1,22 @@
+데이터베이스와 직접적으로 맞닿는 핵심적인 클래스
+- entity를 기준으로 테이블 생성
+- Builder 패턴을 사용해서 필요한 값만 넣음
+
+PostEntity 객체가 곧 DB의 한 행(row)
+-> 기본 키는 id이고, 나머지는 속성임을 명시하는 클래스
+
+@Entity
+데이터베이스 테이블과 매핑
+- JPA가 이 클래스를 테이블로 인식
+- 데이터베이스 테이블로 매핑할 수 있게 함
+
+@Id
+해당 필드가 기본 키임을 나타냄
+- JPA에서 이 필드는 각 행을 고유하게 식별하는 기준
+
+@GeneratedValue
+기본 키의 값을 자동 생성할 때 어떤 전략을 쓸지 지정
+GenerationType.IDENTITY는 자동 증가
+
+@Getter, @Setter (Lombok)
+보일러플레이트 제거
\ No newline at end of file
diff --git a/src/main/java/com/example/devSns/repository/PostRepository.java b/src/main/java/com/example/devSns/repository/PostRepository.java
new file mode 100644
index 0000000..d6e24c5
--- /dev/null
+++ b/src/main/java/com/example/devSns/repository/PostRepository.java
@@ -0,0 +1,7 @@
+package com.example.devSns.repository;
+
+import com.example.devSns.entity.PostEntity;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface PostRepository extends JpaRepository<PostEntity, Long> {
+}
diff --git a/src/main/java/com/example/devSns/repository/explanation b/src/main/java/com/example/devSns/repository/explanation
new file mode 100644
index 0000000..235ff10
--- /dev/null
+++ b/src/main/java/com/example/devSns/repository/explanation
@@ -0,0 +1,5 @@
+데이터베이스 접근 (JPA 인터페이스)
+
+PostRepository<T, ID>
+상속만 하면 기본 CRUD가 다 생김
+- save, findAll, findById, deleteById
diff --git a/src/main/java/com/example/devSns/service/PostService.java b/src/main/java/com/example/devSns/service/PostService.java
new file mode 100644
index 0000000..c66c5cb
--- /dev/null
+++ b/src/main/java/com/example/devSns/service/PostService.java
@@ -0,0 +1,46 @@
+package com.example.devSns.service;
+
+import com.example.devSns.entity.PostEntity;
+import com.example.devSns.repository.PostRepository;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+
+@Service
+@Transactional(readOnly = true)
+public class PostService {
+    private final PostRepository postRepository;
+
+    // 생성자
+    public PostService(PostRepository postRepository) {
+        this.postRepository = postRepository;
+    }
+
+    public List<PostEntity> getAllPosts() {
+        return postRepository.findAll();
+    }
+
+    public PostEntity getPost(Long id) {
+        return postRepository.findById(id).orElseThrow();
+    }
+
+    @Transactional
+    public PostEntity createPost(PostEntity postEntity) {
+        return postRepository.save(postEntity);
+    }
+
+    @Transactional
+    public PostEntity updatePost(Long id, PostEntity updated) {
+        PostEntity postEntity = postRepository.findById(id).orElseThrow();
+        postEntity.setTitle(updated.getTitle());
+        postEntity.setContent(updated.getContent());
+        return postRepository.save(postEntity);
+    }
+
+    @Transactional
+    public void deletePost(Long id) {
+        postRepository.deleteById(id);
+    }
+
+}
\ No newline at end of file
diff --git a/src/main/java/com/example/devSns/service/explanation b/src/main/java/com/example/devSns/service/explanation
new file mode 100644
index 0000000..09b39f6
--- /dev/null
+++ b/src/main/java/com/example/devSns/service/explanation
@@ -0,0 +1,33 @@
+비지니스 로직 담당
+
+PostService
+
+@Service
+비지니스 로직이 모이는 곳
+- 트랜잭션을 붙여야 할 때도 주로 서비스에서
+- 의존성 주입 (생성자 주입)
+
+@Transactional(readOnly = true)
+읽기 성능 최적화
+- 원자성 보장
+- 안전빵
+
+private final PostRepository postRepository;
+- 의존성으로 받는 레포지토리
+- 생성자 주입
+- JpaRepository<PostEntity, Long> 상속
+
+findAll()
+- 모든 게시글 조회
+
+findById()
+- getPost 함수에서 PK(id)로 단건 조회
+- updatePost 함수에서 수정 대상 로드, 필드 갱신, 저장
+
+save
+- 새 엔터티 저장
+- id가 없으면 persist, 있으면 merge
+
+deleteById
+- PK(id)로 삭제
+
diff --git a/src/main/resources/application.properties b/src/main/resources/application.properties
index f3f10af..8bef822 100644
--- a/src/main/resources/application.properties
+++ b/src/main/resources/application.properties
@@ -1 +1,23 @@
 spring.application.name=devSns
+
+# ?? ??
+server.port=8080
+
+# H2 ???? DB
+spring.datasource.url=jdbc:h2:mem:testdb;MODE=MySQL;DATABASE_TO_UPPER=false
+spring.datasource.driver-class-name=org.h2.Driver
+spring.datasource.username=sa
+spring.datasource.password=
+
+# JPA
+spring.jpa.hibernate.ddl-auto=update
+spring.jpa.show-sql=true
+spring.jpa.properties.hibernate.format_sql=true
+
+# H2 ??
+spring.h2.console.enabled=true
+spring.h2.console.path=/h2-console
+
+# Thymeleaf(??? ??? ?? ?)
+spring.thymeleaf.cache=false
+
diff --git a/src/main/resources/templates/detail.html b/src/main/resources/templates/detail.html
new file mode 100644
index 0000000..bdaeae8
--- /dev/null
+++ b/src/main/resources/templates/detail.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<html xmlns:th="http://www.thymeleaf.org">
+<body>
+    <h2 th:text="${post.title}">제목</h2>
+    <h2 th:text="${post.content}">내용</h2>
+    <p>
+        <b>작성자:</b>
+        <span th:text="${post.author}"></span>
+    </p>
+
+    <a th:href="@{|/posts/${post.id}/edit|}">
+        <button type="button">수정</button>
+    </a>
+    <form th:action="@{|/posts/${post.id}/delete|}" method="post">
+        <button type="submit">삭제</button>
+    </form>
+    <a th:href="@{|/posts|}">
+        <button type="button">게시글 보기</button>
+    </a>
+</body>
+</html>
\ No newline at end of file
diff --git a/src/main/resources/templates/edit.html b/src/main/resources/templates/edit.html
new file mode 100644
index 0000000..777a6e3
--- /dev/null
+++ b/src/main/resources/templates/edit.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<html xmlns:th="http://www.thymeleaf.org">
+<body>
+    <h2>게시글 수정</h2>
+
+    <form th:action="@{|/posts/${post.id}/update|}" method="post" th:object="${post}">
+        <label>제목:</label><br/>
+        <input type="text" th:field="*{title}" /><br/><br/>
+
+        <label>내용:</label><br/>
+        <textarea th:field="*{content}" rows="6" cols="40"></textarea><br/><br/>
+
+        <button type="submit">수정 완료</button>
+    </form>
+
+    <br/>
+    <a th:href="@{|/posts/${post.id}|}">취소</a>
+</body>
+</html>
\ No newline at end of file
diff --git a/src/main/resources/templates/form.html b/src/main/resources/templates/form.html
new file mode 100644
index 0000000..52849d8
--- /dev/null
+++ b/src/main/resources/templates/form.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html xmlns:th="http://www.thymeleaf.org">
+<body>
+    <h2>새 글 작성</h2>
+    <form action="/posts" method="post" th:object="${post}">
+        <input type="text" th:field="*{title}" placeholder="제목" />
+        <textarea th:field="*{content}" placeholder="내용"></textarea>
+        <input type="text" th:field="*{author}" placeholder="작성자" />
+        <button type="submit">저장</button>
+    </form>
+</body>
+</html>
\ No newline at end of file
diff --git a/src/main/resources/templates/list.html b/src/main/resources/templates/list.html
new file mode 100644
index 0000000..c444459
--- /dev/null
+++ b/src/main/resources/templates/list.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<html xmlns:th="http://www.thymeleaf.org">
+<body>
+    <h2>게시판</h2>
+    <a href="/posts/new">새 글 쓰기</a>
+    <ul>
+        <li th:each="post : ${posts}">
+            <a th:href="@{|/posts/${post.id}|}" th:text="${post.title}"></a>
+            </br>
+            <small>
+                작성일:
+                <span th:text="${#temporals.format(post.createdAt, 'yyyy-MM-dd HH:mm')}"></span>
+                /
+                수정일:
+                <span th:text="${#temporals.format(post.updatedAt, 'yyyy-MM-dd HH:mm')}"></span>
+            </small>
+        </li>
+    </ul>
+</body>