It is a software that is hidden in our computer, do you remember the "Trojan Horse" ?, This is the modern version for computer systems.
Similar to Viruses, they have the ability to copy (duplicate), using the automatic parts of the operating system.
What is an Adware ?, Are programs that basically show advertising, often installed in our browsers or even as pop-ups.
"The worst virus is the human being", why ?, it is very important to understand that we have access to a lot of information, and very little knowledge, this leads us to make very serious errors regarding security, so how to fix it ?.
What is a Spyware ?, is a spy program that collects information from a computer and then transmits this information to an external entity without the knowledge or consent of the owner of the computer.