[Mozilla Clubs](https://teach.mozilla.org/clubs/) is a program to teach digital skills and web literacy. It focuses on regular, in-person learning tailored to the needs and opportunities of local communities. It harnesses the web as a unique public resource to learn and grow.
A command line (or 'command prompt') is in many respects the opposite of a Graphical User Interface (GUI). The CLI is a terminal window on your device where you can interact with a computer at a more fundamental level than the GUI. An example is the difference between going to a website using a browser to see if it's working, versus sending a [Ping](#ping) via a command line to see if it's available.
Creative Commons licenses allow those creating digital artefacts to choose under what conditions their work can be remixed. There are different kinds of licenses, some more permissive and some more restrictive. An up-to-date list of these, along with a guided license chooser can be found at [creativecommons.org](http://creativecommons.org)
Limitations set around a particular activity, project or program to facilitate directed thinking, planning and creation.
The Domain Name System, or DNS, is the way that **URLs** are translated into **IP addresses**. This allows words, easily understandable by humans, to be converted into numbers, which are more easily understood by computers.
Within a network of computers, a hop is one part of the path a data [packet](#packet) takes between its source and destination. For example, a data packet may be sent from a computer to a router, on to the [ISP](#) and then to the [DNS](#) to be resolved into an [IP address](#). This happens every time a user types in the [URL](#) of a website and connects to the [web server](#) providing the resource. To see how many hops it takes to get from the source to the destination, a [traceroute](#) program can be used.
An IP address is a numerical label given to each device on a computer network. This may be your **Local Area Network (LAN)** or the Internet. IP addresses are given to everything from computers to printers to mobile devices such as printers. An example of how these are used is when **routers** send data coming from the internet to the correct device based on its IP address.
"An Internet Service Provider (ISP) is an organization that provides services for accessing, using, or participating in the Internet" (Wikipedia). Having a **router** in your home or business allows computers to talk to each other on the **LAN** but to connect to the Internet your router will also need to connect via an ISP.
A Local Area Network, or LAN connects devices together within a particular area. For example, if you have a **router** in your home then that has a LAN. These can be more or less complicated; some LANs are huge and cover entire organisations or university campuses.
A packet is a formatted unit of data to be sent across a network. Packet-based networks are more efficient than bit-stream networks as packets can be shared among users. Each packet contains two types of data: control information and user data. An example of this would be the URL or IP address of a search engine _(the control information)_ and your search term _(the user data)_.
Users and software programs can send a ping to an [IP address](#) on a network. This can be used to judge the speed of a network connection, or to see whether the machine / website / resource at the IP address is currently available. A packet of data is sent between one *IP address* (normally the user's device) and another device on the network (normally a website). If this happens quickly, then the connection is said to have _low latency_. This is important for many types of realtime applications, including online games.
A remix is when an existing artefact is taken and altered in some way. This can be done in a very subtle, barely noticeable way, such as when someone takes some text and changes a few words. It can also be done in a dramatic way, for example when several images are combined together using filters and other artistic techniques. Any kind of media can be remixed. Related: *Creative Commons licenses*.
A router moves data packets between computer networks. The most common example of this is when data coming from the Internet via an **ISP** is sent to a particular device based on its **IP address**
Traceroute is a diagnostic tool for displaying the route that a **packet** of data has taken across a network. It is useful for finding **hops** and measuring **ping** times between the source and destination.
A Uniform Resource Locator, or URL, is also known as a web address. This is what you see when you visit a website - for example, [https://mozilla.org](https://mozilla.org). These are translated into **IP addresses** that computers can understand by **DNS**.
A web server is a computer that hosts websites and other services via the Internet.