Index: iknow-api/DTOs/UserDTO.cs
===================================================================
--- iknow-api/DTOs/UserDTO.cs	(revision 277bd721a2fad95bc066942c62c39118a9e2a901)
+++ iknow-api/DTOs/UserDTO.cs	(revision 9538edc6e5b4e46a44364cdbc2c10b0ae05dcc98)
@@ -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
     }
 }