What is a port scan?
In order to understand what a port scan is, we first need to explain what a port is. Ports are connection portals to a computer. Each TCP/IP communication needs to originate from a port on one computer and go to a port on another computer to establish a connection. There are over 65,000 ports available to a TCP/IP stack on a computer. Certain services use a standard port to establish a connection, and other programs may pick up the first port your operating system assigns to them. For example, if you run a web server on your computer, the www service uses port 80 and listens on it for connection, and in turn, when people enter your web address in their browsers, their browsers go to your address and try to establish a connection to port 80 of your computer to grab the information you provide. But here’s the important part: If you are not running a service such as www on your port 80, your computer sends a message to their browser, informing them that your port 80 is closed, at which po
