Spyware is software that can install itself or run on your computer without getting your consent or providing you with adequate notice or control. Spyware might not display symptoms after it infects your computer, but many malicious or unwanted programs can affect how your computer runs. For example, spyware can monitor your online behavior or collect information about you (including information that can identify you or other sensitive information), change settings on your computer, or cause your computer to run slowly.

Spyware is a program that runs on your computer and, again, tracks your habits and tailors these patterns for advertisements. Because it is a computer program rather than just a bit of text in a cookie, spyware can also do things to ensure that the spyware keeps running and keeps influencing what you see.