什么是拥塞控制？
What is congestion control?
拥塞控制防止过多数据涌入网络导致路由器与链路过载、大面积丢包。TCP 用慢启动、拥塞避免、快重传等机制动态调整发送速率，在吞吐与公平之间取得平衡。
Congestion control prevents too much data from flooding the network and overloading routers and links, which would cause massive loss. TCP uses slow start, congestion avoidance, and fast retransmit to dynamically tune its sending rate, balancing throughput and fairness.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
IETF RFC 9293（TCP）
IETF RFC 9293 (TCP)
#拥塞控制 #TCP #慢启动
什么是 DNS（域名系统）？
What is DNS (Domain Name System)?
DNS 是互联网的「电话簿」，负责把人类易记的域名（如 example.com）翻译成机器使用的 IP 地址。当在浏览器输入网址时，系统会向 DNS 服务器查询对应的地址。它让用户无需记忆复杂的数字串。
DNS is the Internet's phone book, translating human-friendly domain names such as example.com into the IP addresses machines use. When you type a URL in a browser, the system queries a DNS server for the corresponding address. It lets users avoid memorizing complex numeric strings.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-05
来源 · Source
互联网工程任务组（IETF）,《Domain names - implementation and specification》,RFC 1035,1987 (DOI: 10.17487/rfc1035)
IETF, 'Domain names - implementation and specification', RFC 1035, 1987, DOI: 10.17487/rfc1035
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.17487/rfc1035; RFC 1035
#DNS #域名 #解析
HTTP 请求-响应过程是怎样的？
How does the HTTP request-response cycle work?
浏览器作为客户端向服务器发送 HTTP 请求（含方法、URL、头），服务器处理并返回状态码、响应头和正文。例如 200 表示成功、404 表示找不到资源。HTTPS 在此基础上加了加密层 TLS。
A browser acting as a client sends an HTTP request (method, URL, headers) to a server, which processes it and returns a status code, response headers, and body. For example, 200 means success and 404 means the resource was not found. HTTPS adds the TLS encryption layer on top.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
IETF RFC 9110（HTTP Semantics）
IETF RFC 9110 (HTTP Semantics)
#HTTP #请求响应 #状态码
OSI 七层模型是什么？
What is the OSI seven-layer model?
OSI 模型把网络通信分成七层：物理层、数据链路层、网络层、传输层、会话层、表示层和应用层。每一层只与上下相邻层交互，各司其职，便于设计和排错。现实中互联网更常用简化的 TCP/IP 四层模型。
The OSI model divides network communication into seven layers: physical, data link, network, transport, session, presentation, and application. Each layer interacts only with its neighbors, with clear responsibilities that ease design and troubleshooting. In practice the Internet uses the simpler four-layer TCP/IP model.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Kurose & Ross,《Computer Networking: A Top-Down Approach》第8版,Pearson,2021
J. F. Kurose and K. W. Ross, Computer Networking, 8th ed., Pearson, 2021
#OSI #网络模型 #分层
什么是 CDN（内容分发网络）？
What is a CDN (Content Delivery Network)?
CDN 是把网站内容缓存到全球各地边缘服务器的网络，让用户从离自己最近的节点获取数据。它能显著加快网页、视频和图片的加载速度，并分担源站压力。大型网站几乎都依赖 CDN 提供服务。
A CDN is a network that caches website content on edge servers around the world so users fetch data from the nearest node. It greatly speeds up loading of web pages, videos, and images and offloads the origin server. Large websites almost all rely on CDNs.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Kurose & Ross,《Computer Networking: A Top-Down Approach》第8版,Pearson,2021
J. F. Kurose and K. W. Ross, Computer Networking, 8th ed., Pearson, 2021
#CDN #缓存 #加速
什么是 TCP 三次握手？
What is the TCP three-way handshake?
三次握手是 TCP 建立可靠连接的过程：客户端先发 SYN，服务器回 SYN+ACK，客户端再发 ACK 确认。这样双方都确认了彼此的发送和接收能力。握手完成后才开始真正传输数据。
The three-way handshake is how TCP establishes a reliable connection: the client sends SYN, the server replies with SYN+ACK, and the client sends back ACK. This confirms both sides' ability to send and receive. After the handshake, actual data transfer begins.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-05
来源 · Source
互联网工程任务组（IETF）,《Transmission Control Protocol》,RFC 793,1981 (DOI: 10.17487/rfc793)
IETF, 'Transmission Control Protocol', RFC 793, 1981, DOI: 10.17487/rfc793
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.17487/rfc793; RFC 793
#三次握手 #TCP #连接
什么是 DNS？
What is DNS?
域名系统（DNS）把人们易记的域名（如 example.com）翻译成机器使用的 IP 地址。它像电话簿，通过分布式的层级服务器完成查询，让我们无需记住一长串数字。
The Domain Name System (DNS) translates human-friendly domain names (like example.com) into the IP addresses machines use. Like a phone book, it resolves queries through a distributed, hierarchical set of servers so we needn't memorize long numbers.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-05
来源 · Source
互联网工程任务组（IETF）,《Domain names - concepts and facilities》,RFC 1034,1987 (DOI: 10.17487/rfc1034)
IETF, 'Domain names - concepts and facilities', RFC 1034, 1987, DOI: 10.17487/rfc1034
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.17487/rfc1034; RFC 1034
#DNS #域名 #解析
路由器是什么？
What is a router?
路由器是连接不同网络的设备，依据目的 IP 地址查表选择最佳路径，把数据包转发到下一站。家庭路由器还常兼任交换机、无线接入和地址分配（NAT/DHCP）功能。
A router is a device that connects different networks; it consults tables based on the destination IP to choose the best path and forwards packets to the next hop. Home routers often also act as a switch, wireless access point, and address allocator (NAT/DHCP).
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-02
来源 · Source
《计算机网络：自顶向下方法》（Kurose & Ross）
Computer Networking: A Top-Down Approach (Kurose & Ross)
独立核验依据 · Independent verification: 核验依据 1 ISBN 9787111712367（豆瓣书目条目: 计算机网络：自顶向下方法）
#路由器 #数据包 #转发
HTTP 和 HTTPS 有什么区别？
What is the difference between HTTP and HTTPS?
HTTP 是浏览器和网站之间传输网页的协议；HTTPS 是在 HTTP 之上加入 TLS/SSL 加密的版本。HTTPS 能防止通信内容被窃听和篡改，并验证网站身份。如今绝大多数网站都已启用 HTTPS 以保护用户隐私。
HTTP is the protocol for transferring web pages between browsers and websites; HTTPS is the encrypted version that adds TLS/SSL on top of HTTP. HTTPS prevents eavesdropping and tampering and verifies the website's identity. Today most websites enable HTTPS to protect user privacy.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Kurose & Ross,《Computer Networking: A Top-Down Approach》第8版,Pearson,2021
J. F. Kurose and K. W. Ross, Computer Networking, 8th ed., Pearson, 2021
#HTTP #HTTPS #加密
什么是 TCP 和 UDP？
What are TCP and UDP?
TCP 和 UDP 是互联网传输层两大协议。TCP 提供可靠、有序、面向连接的传输，适合网页和文件传输；UDP 不保证可靠但速度更快、延迟更低，适合视频通话和游戏。选择哪一种取决于对可靠性和实时性的要求。
TCP and UDP are the two main transport-layer protocols of the Internet. TCP provides reliable, ordered, connection-oriented transmission, suited to web pages and file transfer; UDP is faster with lower latency but no reliability guarantee, suited to video calls and games. The choice depends on the need for reliability versus real-time performance.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-05
来源 · Source
互联网工程任务组（IETF）,《Transmission Control Protocol》,RFC 793,1981 (DOI: 10.17487/rfc793)
IETF, 'Transmission Control Protocol', RFC 793, 1981, DOI: 10.17487/rfc793
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.17487/rfc793; RFC 793
#TCP #UDP #传输层
我们发的消息是怎么传到朋友手机上的？
How does a message we send reach a friend's phone?
消息先被切成小「数据包」，沿着网络经过路由器一跳一跳地传向朋友的手机。每个包都写着对方的地址，到达后再重新拼成完整消息。就算中间某段线路断了，也能绕别的路过去。
The message is split into small packets that travel hop by hop through routers toward the friend's phone. Each packet carries the destination address and is reassembled into the full message on arrival. Even if one link breaks, it can take another route.
难度 入门 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
Postel, J.,《Internet Protocol》,互联网工程任务组 (IETF) RFC 791,1981 (DOI: 10.17487/rfc791)
J. Postel, 'Internet Protocol', IETF RFC 791, 1981, DOI: 10.17487/rfc791
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.17487/rfc791
#网络 #数据包 #传输
什么是 Cookie？
What is a cookie?
Cookie 是网站保存在你浏览器里的一小段文本数据，用来记住你的登录状态、偏好等信息。下次访问同一网站时浏览器会把 Cookie 发回服务器。它让无状态的 HTTP 协议能够「记住」用户。
A cookie is a small piece of text data a website stores in your browser to remember your login status, preferences, and similar information. On your next visit the browser sends the cookie back to the server. It lets the stateless HTTP protocol remember users.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Kurose & Ross,《Computer Networking: A Top-Down Approach》第8版,Pearson,2021
J. F. Kurose and K. W. Ross, Computer Networking, 8th ed., Pearson, 2021
#Cookie #会话 #浏览器