Index: iknow-api/DTOs/UserDTO.cs
===================================================================
--- iknow-api/DTOs/UserDTO.cs	(revision 271178d597db61c1a18da2c7f3c6bd48512e23f0)
+++ iknow-api/DTOs/UserDTO.cs	(revision cb8e531a0773f83ac2b272beb7f03b05eadb7a06)
@@ -1,8 +1,42 @@
 namespace iknow_api.DTOs
 {
-    public class UserDto
+    // Login DTO
+    public class LoginDto
     {
-        public string Username { get; set; } = null!;
-        public string Password { get; set; } = null!;
+        public string Email { get; set; } = string.Empty;
+        public string Password { get; set; } = string.Empty;
+    }
+
+    // Registration DTO
+    public class RegisterDto
+    {
+        public string Name { get; set; } = string.Empty;
+        public string Surname { get; set; } = string.Empty;
+        public string? Index { get; set; }
+        public string Email { get; set; } = string.Empty;
+        public string Password { get; set; } = string.Empty;
+        public DateTime Bday { get; set; }
+        public UserRole Role { get; set; }
+    }
+
+    // User response DTO (for returning user data without password)
+    public class UserResponseDto
+    {
+        public int Id { get; set; }
+        public string? Name { get; set; }
+        public string? Surname { get; set; }
+        public string? Index { get; set; }
+        public string? Email { get; set; }
+        public DateTime Bday { get; set; }
+        public DateTime CreatedAt { get; set; }
+        public UserRole Role { get; set; }
+    }
+
+    // User role enum
+    public enum UserRole
+    {
+        Admin,
+        Professor,
+        Student
     }
 }