Security software is a piece of software that protects your system, hence data, from people with malicious intents. There are different categories of security software. Following is a list of broad categories of security software and a brief description of how they work.
An antivirus program protects your device from viruses. Viruses are small programs written by people with malicious intents. Once your system is infected with a virus, it can send your private data files to the people. Some viruses take control of your device and perform the tasks without your knowledge and consent.
An antivirus program runs in the background and scans every file on your system. It will scan all programs running on your system and the files you download from the internet. USB drives are very effective in spreading viruses. So, modern antivirus programs will scan any files that you try to copy from the USB drive.
Firewall is another type of security software that limits the access to your computer. When you are connected to a network, internet for example, you continuously send and receive data. If there is no firewall installed on your device, people with malicious intents will be able to connect to your device and perform unauthorized actions. A firewall program also runs in the background and blocks unauthorized attempts from performing actions of your device.
Adware is another kind of malicious software that tries to show you ads and directs your browser to the sites where you do not want to go. It is different from a virus as it does not intend to steal your private data. Although less harmful as compared to viruses, adware programs make your device very slow and distract you from the task that you want to accomplish. Anti-adware programs find and remove adware from your device.