When talking about computer security, you will come across the word "spyware" a lot. It's important to understand what this word means--and what it doesn't mean--so you can protect yourself without going to excessive lengths.

Definition

In a nutshell, spyware is questionable software installed on your computer that monitors certain user behaviors and sends this information over the Internet to be collected and inspected.

How Spyware Gets In

Spyware is often bundled (sometimes secretly) with legitimate-looking software that you download from the Internet. You can sometimes opt out of installing this spyware, and other times removing the spyware will disable the program.

Degrees of Behavior

Some spyware only makes a note of what websites you visit, what search words you use, and when and how often you use the Internet on a given day. However, other spyware might attempt to capture your password, credit card numbers or other sensitive information when you type it in.

Protect Yourself

Lavasoft and Safer Networking offer Ad-Aware and Spybot Search & Destroy, respectively--two free software programs to scan and clean your computer of spyware. They can also install little programs that sit in the background and monitor for spyware installation (see Resources).

Read the Fine Print

When you are installing software that you have downloaded from the Internet, it's important to take a close look at the EULA (End User License Agreement), a sort of contract that appears in a window during installation. Here, you can find mentions of spyware and decide to not install the software.

Source:

Understanding Spyware

Why You Should Read the EULA