Hacker Definition While this term originally referred to a clever or expert programmer, it is now more commonly used to refer to someone who can gain unauthorized access to other computers. A hacker can "hack" his or her way through the security levels of a computer system or network. This can be as simple as figuring out somebody else's password or as complex as writing a custom program to break another computer's security software. Hackers are the reason software manufacturers release periodic...

Encryption Definition Encryption is the process of converting data to an unrecognizable or "encrypted" form. It is commonly used to protect sensitive information so that only authorized parties can view it. This includes files and storage devices, as well as data transferred over wireless networks and the Internet. You can encrypt a file, folder, or an entire volume using a file encryption utility such as GnuPG or AxCrypt. Some file compression programs like Stuffit Deluxe and 7-Zip can also en...

TFTP Definition Stands for "Trivial File Transfer Protocol." TFTP is a file transfer protocol similar to FTP, but is much more limited. Unlike FTP, TFTP does not support authentication and cannot change directories or list directory contents. Therefore, it is most often used to transfer individual files over a local network. TFTP may also be used to boot a computer system from a network-connected storage device. While FTP connections use the TCP protocol, TFTP connections are made over UDP, whi...

OSI Model Definition The OSI (Open Systems Interconnection) model was created by the ISO to help standardize communication between computer systems. It divides communications into seven different layers, which each include multiple hardware standards, protocols, or other types of services. The seven layers of the OSI model include: The Physical layer The Data Link layer The Network layer The Transport layer The Session layer The Presentation layer The Application layer When one ...

Username Definition A username is a name that uniquely identifies someone on a computer system. For example, a computer may be setup with multiple accounts, with different usernames for each account. Many websites allow users to choose a username so that they can customize their settings or set up an online account. For example, your bank may allow you to choose a username for accessing your banking information. You may need to choose a username in order to post messages to a certain message boa...