Copyright means that the owners of the material have the right to own, sell and distribute with the others.
Software is protected by the copyright law. If the people download the software legally, they can get protected and guaranteed. But, if the people download the software illegally, the are more likely to be damaged by the viruses.
The ways to find whether the software is a genuine are; a product key and security label on the package. 
There’s a way to download the software legally for free (often free), which is open source. But it has much more less functions than the original software.
Difference between antivirus and firewall :
Antivirus is just to prevent the infection from the virus and scan the computer whether they have viruses in the computer or not. But firewall is a software which prevent the personal or financial information in computer to go out and blocking the viruses to come into the computer.
Top level domain :
.com : use for the worldwide use
.ac.[country] : use from the school
.edu : use from the educational purpose
.gov : the website running by government
.org : the website running by organisation
.co.[country] : company in certain country
IGCSE ICT BLOG 