Answer:
<em><u>Historically, 63 minute/550 MB (12 cm) and 18 minute/158 MB (8 cm) discs were once available but are now rendered obsolete by advances in recording technology. Currently, 74 minute/650 MB, 80 minute/700 MB (12 cm) and 21 minute/185 MB (8 cm) discs are the market standards</u></em>.
They are examples of constraints.
The answer is a firewall. It is a system that will block potentially harmful software or websites from accessing your computer.
Positive impacts are
1. Communicating with people
2. Daily update of what going on in the world
3. learn new things
Negative impacts are
1. Viruses
2. Private information shared
3. Less face to face conversations