All computers have thousands of ports that are used as communication paths between the PC's applications and services that are required on a network. Ports are like little open doors that allow two or more applications to talk to each other. Your computer has 65537 ports that may be used for various types of communication and data exchange. Of these, only 1025 are commonly used and designated as "well known ports". All software applications require the use of ports in order to work, but the majority of ports are not used for anything, creating a potential security risk if left open.

Quite often certain unneeded ports are left wide open by operating systems, browsers, and other installed applications, leaving secret back doors open on your computer. Most software developers frequently issue patches, service packs and hot fixes when they discover a security hole such as this, but many still go undetected. Software updates will close the open ports that the developer is aware of, which is why it's so important to perform regular computer updates.

Hackers and malicious software applications take advantage of open ports to infiltrate your computer. Spyware, viruses and other types of malware utilize open ports to retrieve information, destroy data and corrupt operating systems. Since unneeded open ports represent the "unlocked back doors" into your computer, it's important to prevent unauthorized access. A good way to see how vulnerable your computer is to outsiders is to do a port scan. Many security vendors offer an online port scan that will show you exactly how far into your computer a hacker can get. Once you learn what your PC