---
title: Useful terms
description: Reference information for Useful terms in Zero Trust networking.
image: https://developers.cloudflare.com/zt-preview.png
---

> Documentation Index  
> Fetch the complete documentation index at: https://developers.cloudflare.com/cloudflare-one/llms.txt  
> Use this file to discover all available pages before exploring further.

[Skip to content](#%5Ftop) 

# Useful terms

Review terminology for Cloudflare Tunnels.

## Tunnel

A tunnel is a secure, outbound-only pathway you can establish between your origin and Cloudflare's global network. Each tunnel you create will be assigned a [name](#tunnel-name) and a [UUID](#tunnel-uuid).

## Tunnel UUID

A tunnel UUID is an alphanumeric, unique ID assigned to a tunnel. The tunnel UUID can be used whenever you need to reference a specific tunnel.

## Tunnel name

A tunnel name is a unique, user-friendly identifier that you choose for a tunnel. Since a tunnel can proxy traffic to multiple services, tunnel names do not need to be hostnames. For example, you can assign your tunnel a name that represents your application/network, a particular server, or the cloud environment where it runs.

## Connector

The connector, referred to as `cloudflared`, establishes connectivity from your origin server to the Cloudflare global network. Each `cloudflared` instance creates four long-lived connections to at least two distinct data centers within Cloudflare's global network. This built-in redundancy means that if an individual connection, server, or data center goes down, your origin remains available.

## Replica

A replica is an additional instance of `cloudflared` running the same tunnel on a different host. You can create and configure a tunnel once, then run it through multiple replicas for redundancy. DNS records and Cloudflare Load Balancers continue to point to the tunnel (`UUID.cfargotunnel.com`), while Cloudflare distributes traffic across the available replicas. There is no guarantee about which replica will be chosen — Cloudflare routes to the geographically closest one. Replicas are typically deployed to keep a tunnel available if a host running `cloudflared` goes offline.

## Remotely-managed tunnel

A remotely-managed tunnel is a [tunnel](#tunnel) that was created in the [Cloudflare dashboard ↗](https://dash.cloudflare.com/) under **Zero Trust** \> **Networks** \> **Connectors** \> **Cloudflare Tunnels**. Tunnel configuration is stored in Cloudflare, which allows you to manage the tunnel from the dashboard or using the [API](https://developers.cloudflare.com/api/resources/zero%5Ftrust/subresources/tunnels/subresources/cloudflared/subresources/configurations/methods/get/).

## Locally-managed tunnel

A locally-managed tunnel is a [tunnel](#tunnel) that was created by running `cloudflared tunnel create <NAME>` on the command line. Tunnel configuration is stored in your local [cloudflared directory](#default-cloudflared-directory). For terminology specific to locally-managed tunnels, refer to the [Locally-managed tunnel glossary](https://developers.cloudflare.com/cloudflare-one/networks/connectors/cloudflare-tunnel/do-more-with-tunnels/local-management/local-tunnel-terms/).

## Quick tunnels

Quick tunnels, when run, will generate a URL that consists of a random subdomain of the website `trycloudflare.com`, and point traffic to localhost on port `8080`. If you have a web service running at that address, users who visit the generated subdomain will be able to visit your web service through Cloudflare's network. Refer to [TryCloudflare](https://developers.cloudflare.com/cloudflare-one/networks/connectors/cloudflare-tunnel/do-more-with-tunnels/trycloudflare/) for more information on how to run quick tunnels.

## Virtual networks

A [virtual network](https://developers.cloudflare.com/cloudflare-one/networks/connectors/cloudflare-tunnel/private-net/cloudflared/tunnel-virtual-networks/) is a software abstraction that allows you to logically segregate resources on your private network. Virtual networks are especially useful for exposing resources which have overlapping IP routes. To connect to a resource, end users would select a virtual network in their Cloudflare One Client settings before entering the destination IP.

```json
{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/directory/","name":"Directory"}},{"@type":"ListItem","position":2,"item":{"@id":"/cloudflare-one/","name":"Cloudflare One"}},{"@type":"ListItem","position":3,"item":{"@id":"/cloudflare-one/networks/","name":"Networks"}},{"@type":"ListItem","position":4,"item":{"@id":"/cloudflare-one/networks/connectors/","name":"Connectors"}},{"@type":"ListItem","position":5,"item":{"@id":"/cloudflare-one/networks/connectors/cloudflare-tunnel/","name":"Cloudflare Tunnel"}},{"@type":"ListItem","position":6,"item":{"@id":"/cloudflare-one/networks/connectors/cloudflare-tunnel/get-started/","name":"Get started"}},{"@type":"ListItem","position":7,"item":{"@id":"/cloudflare-one/networks/connectors/cloudflare-tunnel/get-started/tunnel-useful-terms/","name":"Useful terms"}}]}
```