Which software specifically collects user data and sends it without the user’s knowledge?

The choice of spyware aligns with the definition of software that specifically collects user data and sends it without the user’s knowledge. Spyware is designed to secretly monitor user activity, gather sensitive information, and transmit that data to a third party, often without any consent from the user. This can include collecting information such as browsing habits, login credentials, and other personal data, which fundamentally infringes on user privacy.

The key feature of spyware is its stealthy operation; it typically runs in the background without the user’s awareness, making it particularly dangerous. Users are often unaware that their data is being collected, which differentiates spyware from other software types.

In contrast, while adware does collect user data, its primary function is to deliver advertisements, making this less intrusive than spyware. Bots can automate tasks online, but they don't necessarily focus on collecting user data without consent. Trojans are malicious programs that trick users into installing them and can perform various harmful actions, including data theft, but their primary purpose is usually broader than just data collection.