Offline:

When a computer or other device is not turned on or connected to other devices, it is said to be “offline”. This is the opposite of being “online”, when a device can readily communicate with other devices. For example, if you try to print to your printer and you get an error saying, “The specified printer could not be found,” the printer is probably offline. Offline can also mean not being connected to the internet. When you disconnect from your Internet Service Provider (ISP) or pull out the Ethernet cable from your computer, your computer is now offline. Some programs, such as web browsers and email programs, have an option to “Work Offline”. This option disables the program’s network connection, meaning no data can be transmitted to or from the computer. This option was more useful when most people used dial-up connections or had to limit data usage. They did not want their computer automatically dialing their ISP or using data whenever a program tried to access the internet. However, since most people now have “always on” connections such as Viasat’s UNLIMITED data plans, there usually is no reason to work offline.

Online:

In general, when a machine is “online” it is turned on and connected to other devices. For example, when a network printer is online, computers connected to that network can print from it. Other devices, such as scanners, video cameras, audio interfaces, tablets, cell phones, smart TVs and others are said to be “online” when they are running and connected to a computer network.

Recently, however, the term “online” usually means being connected “live” to the internet. The connection can be through a phone line, using a DSL modem, a cable line via a cable modem, a satellite network like Viasat internet via a WiFi modem or through a hot spot wireless connection. A computer can also be online via a connection to a home computer network. Technically, computers that are on a shared network are “online” even if they are not connected to the internet. But most networks are routed to a T1 line or other internet connection anyway. When a computer or other device is not “online” it is said to be “offline”.

Open-Source:

A type of computer program whose source code is made available for use or modification. Open-sourced software is released under a license in which the copyright holder grants users the rights to study, edit and distribute the software to anyone and for any purpose. Open-source software is typically developed in a collaborative public manner and made freely available.

Operating System:

Also known as an “OS” this is the software that manages your electronic device. Without an operating system, no software programs can run. The OS is what allocates memory, processes tasks, accesses disks & peripherals and serves as the user interface. The two most common computer operating systems are Microsoft Windows and Apple macOS. Two popular smartphone operating systems are Apple iOS and Android from Google.

Optical Drive:

“Optical” in the computer IT world refers to lasers, which can see and read data on optical discs. These discs include CDs & DVDs. Optical drives have lasers that read these discs, which the computer can understand. Some common types of optical drives include CD-ROM, CD-RW, DVD-ROM, DVD-RW and Blu-ray drives. CD & DVD writers, such as CD-R & DVD-R drives use a laser to read & write data on the discs. The laser used for writing the data is much more powerful than the laser that reads the data, as it “burns” the the disc. While optical drives can spin discs at very high speeds, they are still significantly slower than hard drives, which store data magnetically. However, because optical media is inexpensive and removable, it is the most common format used for distributing computer software and playing media.

Optical Media:

“Media” in the IT computer world refers to various types of data storage. For example, hard drives, CDs, DVDs and USB drives are all different types of media. Optical media refers to discs that are read by a laser. This includes CD-ROMs, DVD-ROMs and all the variations of the two formats including CD-R, CD-RW, DVD-R, DVD+R, Blu-ray and many others. Optical media typically does not have as fast of a seek time as hard drives (the time it takes to access information on different parts of the disk), but it has many other advantages. Because optical discs are not based on magnetic charges like hard drives are, the discs are less likely to lose their data and have a longer shelf life than magnetic media. The discs are also more durable than hard drives and are much cheaper to produce, making them great for backups and for transferring small amounts of data between different computers.

OSD:

On Screen Display (OSD) is an onscreen menu included with most monitors that allows users to make adjustments to the display. Common OSD settings include brightness, contrast and color calibration adjustments. Some monitors also include positioning settings and tilt control.

Outbox:

An outbox is where outgoing email messages are temporarily stored. While you are composing a message, most email programs automatically save a draft of your message in the outbox. The message is then stored in the outbox until it is successfully sent to the recipient. Once the message has been sent, most email programs move the message to the “Sent” or “Sent Messages” folder. While the terms “Outbox” and “Sent Messages” are often used synonymously, technically they have different meanings.

The outbox typically does not contain any messages. This is because all the messages that have been sent have already been transferred to the “Sent Messages” folder or they are being held in the “Draft” folder. Think of an email outbox like the outbox at an office. Mail that is to be delivered is temporarily placed in the outbox until the mailman (or the designated office mail guy) picks up the mail and brings it to the post office. However, the messages in an email outbox are typically delivered immediately (unless a connection to the outgoing SMTP mail server is not available or the connection is currently offline).

Output:

Data generated by a computer is referred to as “output”. This includes data produced at a software level, such as the result of a calculation, or at a physical level, such as a printed document. A basic example of software output is a calculator program that produces the result of a mathematical operation. A more complex example is the results produced by a search engine, which compares keywords to millions of pages in its web page index.

NOTE: The opposite of output is input, which is data that is entered into the computer.

Output Device:

Any device that produces a physical output of information from a computer is called an output device. Since most information from a computer is output in either a visual or auditory format, the most common output devices are the computer’s monitor and speakers. These two devices provide instant feedback to the user’s input, such as displaying characters as they are typed or playing a song selected from a playlist.

While monitors and speakers are the most common output devices, there are many others including headphones, printers, projectors, lighting control systems, audio recording devices, smart devices & robotic machines. A computer without an output device connected to it is pretty useless, since the output is what we interact with. Anyone who has ever had a monitor or printer stop working knows just how true this is. Of course, it is also important to be able to send information to the computer, which requires an input device.

NOTE: Peripherals that output data from the computer are called output devices. Input and output devices are collectively referred to as I/O devices.