# Glossary

# Grunt

Grunt is the JavaScript Task Runner, Grunt and Grunt plugins are installed and managed via npm (opens new window)

# YARN

Yarn (opens new window)is a package manager for your code. It allows you to use and share code with other developers from around the world. Yarn does this quickly, securely, and reliably so you don't ever have to worry.

# NPM

The JavaScript node package manager (opens new window), typically abbreviated in all lowercase as npm, is the default method for managing packages in the Node.js runtime environment. It relies upon a command line client and a database made up of public and premium packages known as the the npm registry. Users can access the registry via the client and browse the many packages available through the npm website. Both npm and its registry are managed by npm, Inc.

# Express

Express (opens new window) is a Fast, un opinionated, minimalist web framework for node.

# Data disk

A disk that contains only data. It does not include an operating system.

# Domain Name

A domain name is a server or network system name that identifies IP resources connected to the Internet. All domain names are unique worldwide.

# Image

An image is a running environment template for Cloud Server instances. It generally includes an operating system and pre-installed software. An image works as a file copy that includes data from one or more disks. These disks can be a single system disk, or a combination of the system disk and data disks.

# Marketplace Image

A marketplace image contains an OS, the preset application environment, and software. You can use marketplace images to create Cloud Server for website building and application development.

# Port

A port is an endpoint of communication in computer networking. This can be hardware port, a logical port, or both. TCP and UDP ports are identified by their port number (an integer from 0 to 65535).

# Secure Shell (SSH)

A cryptographic network protocol for operating network services securely over an unsecured network based at the application layer and transport layer.

# Secure Shell key pair (SSH key pair)

An authentication method available for logging in to Cloud Server instances remotely. An SSH key pair is a pair of keys generated through an encryption algorithm: one key is publically available (the public key) and the other key is kept confidential (the private key).

If you have placed the public key in a Linux instance, you can use the private key to log on to the instance using SSH commands or related tools from a local computer or another instance without a password.

# Snapshot

A copy of data on a disk at a certain time point. There are two types of snapshots, automatic snapshots and user-created snapshots.

# SFTP

SFTP (SSH File Transfer Protocol) is a secure file transfer protocol. It runs over the SSH protocol . It supports the full security and authentication functionality of SSH.

# Security Group

A security group implements access controls for Cloud Server, specifying the communication scope of Cloud Server. You can define different access control rules for a security group, and these rules take effect for all Cloud Server added to this security group. By default, a security group allows all data packets that are sent out from Cloud Server in it, and Cloud Server in the same security group can access each other.