Anti-spyware software is a type of compture
program designed to prevent and detect unwanted spyware program
installations and to remove those programs if installed.
Anti-virus software is software used to prevent,
detect, and remove malware, including computer viruses, worms, and
trojan horses. Such programs may also prevent and remove adware,
spyware, and other forms of malware.
A firewall is a computer software that is designed to block unauthorized
access while permitting authorized communications.