There are several online resources and websites that can help in understanding and learning the concepts from the syllabus for CBSE Class 9. These resources provide a wide range of educational materials, including study notes, video lectures, practice questions, interactive quizzes, and more. Here are some popular online platforms that can be helpful:

1. EduRev:
- EduRev offers comprehensive study materials for CBSE Class 9 across all subjects.
- It provides detailed notes, solved examples, and practice questions for each chapter.
- The platform also offers video lectures and interactive quizzes to reinforce learning.

2. CBSE Official Website:
- The official website of the Central Board of Secondary Education (CBSE) provides access to the curriculum, syllabus, and sample question papers.
- Students can download the NCERT textbooks and supplementary materials from the website.
- It also provides important announcements, circulars, and updates from the board.

3. Khan Academy:
- Khan Academy is a popular online learning platform that offers video lessons, practice exercises, and quizzes for various subjects, including CBSE Class 9.
- The platform provides personalized learning paths and tracks the progress of the students.
- It covers a wide range of topics and concepts from the CBSE curriculum.

4. TopperLearning:
- TopperLearning provides study materials, video lessons, and practice tests for CBSE Class 9.
- It offers interactive learning tools and features to make studying engaging and effective.
- The platform also provides doubt-solving support and expert guidance to students.

5. LearnCBSE:
- LearnCBSE offers free study materials, sample papers, and solutions for CBSE Class 9.
- It provides chapter-wise notes, NCERT solutions, and revision notes to help students grasp the concepts effectively.
- The platform also offers online tests and practice questions for self-assessment.

These online resources and websites can be valuable tools for CBSE Class 9 students to supplement their learning and gain a deeper understanding of the concepts from the syllabus. It is important to utilize these resources effectively and create a consistent study routine to achieve academic success.