Internet glossary

Breaking down the basics from megabits to megabytes, modems to routers, and everything in between.

Definitions of popular internet terms and acronyms

If you’ve ever wondered “What does DSL stand for?” or “What’s the difference between HD and SD?”, you’re in the right place.


The maximum amount of data that can be transferred at any given time via a network or internet connection.


A popular form of high-speed internet access, created in place of dial-up internet. Comes in a variety of forms (DSL, fiber, wireless, etc.).


The act of transferring various forms of data from one device, browser, or network to another, from a server to a client, and often using the internet (e.g., “I downloaded the PDF from my work’s website onto my computer”).


DSL stands for or digital subscriber line and is a form of broadband internet that uses telephone lines to transfer data at higher speeds.


A form of high-speed internet that uses fiber optic cables (bundles of glass wires) to transfer data using light signals.


A built-in computer defense against unwanted viruses and security breaches from external networks.

High definition (HD)

High definition display resolution has a higher pixel count and better quality than standard-definition television.

IP address

An Internet Protocol address is a unique number sequence assigned to every internet-enabled device for network interface identification online.


Mbps (meaning megabits per second) measures data transfer speeds (e.g., “My internet speed is 500 Mbps”).


A megabit is a unit of data used to measure internet speed, equal to approximately one million bits.


A megabyte is a unit of data equal to approximately one million bytes.


A modem wirelessly transmits data from telephone or cable lines onto internet-enabled devices.


Routers are connected to modems (usually with an Ethernet port) and allow devices to connect to private computer networks.

Standard Definition (SD)

The difference between HD and SD comes down to viewing quality on a TV or computer screen. Standard Definition (SD) consists of 480 pixels (opposed to HD, which starts at 1080 pixels). Higher pixel count = better quality.


The ability to steadily stream or transfer video or audio data using a computer network onto a web-enabled device, while simultaneously still receiving data.


The act of moving data from one device, browser, or network to another, from a client to a server (e.g. “I uploaded our vacation photos onto Facebook”).


Wi-Fi uses radio waves to connect various devices to the internet wirelessly (e.g., “Do you know the Wi-Fi password? I’d like to check my email”).

Definitions of Computer and Internet Terms,, accessed May 24, 2019.