The state of being connected to the Internet. When a user is connected to the Internet, he or she is said to be online.
Open Source Code
A program whose source code is available for public inspection and revision. Open source software is often distributed freely, in the hope that the computing community will contribute to the program, helping to identify and eliminate bugs in the program. Two well-known examples of open source programs are the Apache web server and Linux operating system.
Operating System or OS
The operating system can be thought of as an interface between the hardware of the computer and applications (for example a word processing program. For personal computers the most popular operating systems are Mac, Windows, DOS and Linux.