Hint: Used in communication
The answer to this puzzle is:
1. PENCIL
2. CRAYON
3. ESSAY
4. PAPER
5. SCAN
6. NOTE
7. SPEAKER
8. VIDEO
9. SATELLITE
10. GESTURE
11. SIGN
12. PHONE
2. CRAYON
3. ESSAY
4. PAPER
5. SCAN
6. NOTE
7. SPEAKER
8. VIDEO
9. SATELLITE
10. GESTURE
11. SIGN
12. PHONE