What is node
Node has three meanings: 1. Refers to a network node, which is mainly responsible for sending, receiving and forwarding information in the network; 2. Refers to a node in an XML document. Different types of nodes in the document tree are represented by specific Node sub-elements. Interface representation; 3. Refers to Node.js, a js running environment based on Chrome V8 engine.
The operating environment of this article: Windows 7 system, nodejs version 10.16.2, Dell G3 computer.
What is node?
node has many meanings:
1. Network node
A node refers to a computer or other device and a Have an independent address and be connected to a network capable of transmitting or receiving data. Nodes can be workstations, clients, network users, or personal computers, as well as servers, printers, and other network-connected devices. Every workstation, server, terminal device, and network device that has its own unique network address is a network node. Network nodes are mainly responsible for sending, receiving and forwarding information in the network. Network nodes are the interface between computers and networks. Computers send information to other computers through network nodes, and identify and receive information sent by other computers. In large-scale networks, network nodes are generally played by a processor or communication controller. At this time, the network node also has the functions of storage and forwarding and path selection. The network adapter used in the LAN is also a network node.
The two endpoints of the network cable are nodes, and the connection relationship between network cables is established through the nodes. In reality, there are many nodes in the network, such as street intersections, river junctions, telephone transmission points, gates in the power grid, water gates in the river network, etc. Nodes can be represented as vertices, endpoints, and are associated with network lines.
Node Node, node, network node can be a workstation, client, network user or personal computer, or it can also be a server, printer and other network-connected devices.
2. Nodes in XML documents
In the DOM (Document Object Model), the hierarchical structure of the HTML document is represented as a tree structure. The nodes of the tree represent various contents in the document. The tree representation of an HTML document mainly consists of nodes representing elements or tags (such as
and ) and nodes identifying text strings. HTML documents also contain nodes that represent HTML comments. Consider the following simple HTML document:<html> <head> <title>a document</title> </head> <body> <h1>is html document</h1> <p>this is a<i>documnet</i> </body></html>
If you are not familiar with the structure of properties in computer programming, it will be helpful to know some terminology that these properties have borrowed from their family tree. The node directly above a node is its parent. Nodes directly below a node are children of that node. Nodes located at the same level and with the same parent node are siblings. The set of nodes at the next level of a node are the descendants of that node. A node's parent node, grandparent node, and all other nodes above it are the ancestors of that node.
The DOM attribute structure shown in the figure is a tree of various types of NODE objects. The NODE interface defines properties and methods for convenience and operation trees. The childNodes property of the NODE object will return a list of child nodes, and the firstChild, lastChild, nextSibling, previousSibling, and parentNode properties provide methods for traversing the tree. The appendChild(), removeChild(), replaceChild, and insertBefore() methods allow you to add nodes to or remove nodes from the document tree.
Types of nodes
Different types of nodes in the document tree are represented by specific Node sub-interfaces. Each Node object has nodeType properties, which specify the type of node. For example, if a node's nodeType attribute is equal to the constant attributes, these attributes specify the type of the node. For example, if the nodeType attribute of a node is equal to the constant node.ELEMENT_NODE, you know that the Node object is still an Element object, and you can use all the methods and properties defined by the Element interface on it.
3. Node.js
Node.js was released in May 2009 and developed by Ryan Dahl. It is a JavaScript running environment based on the Chrome V8 engine. Use It provides an event-driven, non-blocking I/O model that allows JavaScript to run on the server-side development platform. It makes JavaScript a scripting language on par with server-side languages such as PHP, Python, Perl, and Ruby.
Recommended learning: "nodejs video tutorial"
The above is the detailed content of What is node. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
How to delete node in nvm
Dec 29, 2022 am 10:07 AM
How to delete node with nvm: 1. Download "nvm-setup.zip" and install it on the C drive; 2. Configure environment variables and check the version number through the "nvm -v" command; 3. Use the "nvm install" command Install node; 4. Delete the installed node through the "nvm uninstall" command.
How to use express to handle file upload in node project
Mar 28, 2023 pm 07:28 PM
How to handle file upload? The following article will introduce to you how to use express to handle file uploads in the node project. I hope it will be helpful to you!
How to do Docker mirroring of Node service? Detailed explanation of extreme optimization
Oct 19, 2022 pm 07:38 PM
During this period, I was developing a HTML dynamic service that is common to all categories of Tencent documents. In order to facilitate the generation and deployment of access to various categories, and to follow the trend of cloud migration, I considered using Docker to fix service content and manage product versions in a unified manner. . This article will share the optimization experience I accumulated in the process of serving Docker for your reference.
An in-depth analysis of Node's process management tool 'pm2”
Apr 03, 2023 pm 06:02 PM
This article will share with you Node's process management tool "pm2", and talk about why pm2 is needed, how to install and use pm2, I hope it will be helpful to everyone!
Pi Node Teaching: What is a Pi Node? How to install and set up Pi Node?
Mar 05, 2025 pm 05:57 PM
Detailed explanation and installation guide for PiNetwork nodes This article will introduce the PiNetwork ecosystem in detail - Pi nodes, a key role in the PiNetwork ecosystem, and provide complete steps for installation and configuration. After the launch of the PiNetwork blockchain test network, Pi nodes have become an important part of many pioneers actively participating in the testing, preparing for the upcoming main network release. If you don’t know PiNetwork yet, please refer to what is Picoin? What is the price for listing? Pi usage, mining and security analysis. What is PiNetwork? The PiNetwork project started in 2019 and owns its exclusive cryptocurrency Pi Coin. The project aims to create a one that everyone can participate
Let's talk about how to use pkg to package Node.js projects into executable files.
Dec 02, 2022 pm 09:06 PM
How to package nodejs executable file with pkg? The following article will introduce to you how to use pkg to package a Node project into an executable file. I hope it will be helpful to you!
Token-based authentication with Angular and Node
Sep 01, 2023 pm 02:01 PM
Authentication is one of the most important parts of any web application. This tutorial discusses token-based authentication systems and how they differ from traditional login systems. By the end of this tutorial, you will see a fully working demo written in Angular and Node.js. Traditional Authentication Systems Before moving on to token-based authentication systems, let’s take a look at traditional authentication systems. The user provides their username and password in the login form and clicks Login. After making the request, authenticate the user on the backend by querying the database. If the request is valid, a session is created using the user information obtained from the database, and the session information is returned in the response header so that the session ID is stored in the browser. Provides access to applications subject to
What to do if npm node gyp fails
Dec 29, 2022 pm 02:42 PM
npm node gyp fails because "node-gyp.js" does not match the version of "Node.js". The solution is: 1. Clear the node cache through "npm cache clean -f"; 2. Through "npm install -g n" Install the n module; 3. Install the "node v12.21.0" version through the "n v12.21.0" command.
