LAN
LAN，全称Local Area Network，中文名叫做局域网。
顾名思义，LAN是指在某一区域内由多台计算机互联成的计算机组。一般是方圆几千米以内。局域网可以实现文件管理、应用软件共享、打印机共享、工作组内的日程安排、电子邮件和传真通信服务等功能。局域网是封闭型的，可以由办公室内的两台计算机组成，也可以由一个公司内的上千台计算机组成。
具体到路由器，我们一般组网，都是组建的LAN网络，用户在局域网里通信、传输文件。
其获取到的是内部IP，LAN 内部是交换机。我们可以不连接 WAN 口，把路由器当做普通交换机来使用。
一般用到的LAN的场景：
1，接电脑的网线，需要插到路由器的LAN口。
2，二级路由，一般都是从上级路由的LAN口接线。
WAN
WAN，全称Wide Area Network，中文名叫做广域网。
WAN是一种跨越大的、地域性的计算机网络的集合。通常跨越省、市，甚至一个国家。广域网包括大大小小不同的子网，子网可以是局域网，也可以是小型的广域网。
WAN：接外部 IP 地址用，通常指的是出口，转发来自内部 LAN 接口的 IP 数据包。
基本每个路由器都有WAN口，当然也有路由猫这种特例。
WAN的应用场景：
1，从猫引出的来网线，要插到路由器的WAN口。
2，二级路由，上级网线插到二级路由的WAN口。
WLAN
refer to : https://info.support.huawei.com/info-finder/encyclopedia/en/WLAN.html
What Is WLAN?
A WLAN is a wireless computer network that links two or more devices using wireless communication to form a LAN within a limited area such as a home, school, campus, or office building. A WLAN is a network system wherein Wi-Fi is one of the most common technologies in this system. Therefore, WLAN includes Wi-Fi.
Benefits of WLAN
WLAN technology first appeared in the United States. It was primarily used as a wireless extension of the last-mile network and was mainly applied in households. At that time, the American people had a strong demand for wireless Internet access due to the cabling difficulties (most Americans living in villas with courtyards) and the popularity of laptops and tablets. This in turn accelerated the proliferation of WLANs.
Compared with wired networks, WLANs have the following benefits:
High mobility: It is easy to connect to WLANs that are free from cable and port location constraints. This makes WLANs ideal for scenarios where users are often moving, such as in office buildings, airport halls, resorts, hotels, stadiums, and cafes.
Flexible deployment: WLANs provide wireless network coverage in places with difficult cabling, such as subways and roadways. Wireless network coverage eliminates or reduces complex cabling, thereby simplifying deployment, reducing costs, and facilitating scalability.
Is WLAN and Wi-Fi the Same Thing?
Wi-Fi is a trademark of the WFA, and is also a wireless network communication technology based on IEEE 802.11. The WFA has announced the use of Wi-Fi to improve the interoperability of products in compliance with IEEE 802.11 standards.
WLAN is short for wireless local area network. Quite simply, WLANs provide network communication using radio waves such as lasers and infrared signals, instead of physical connections. They provide wireless network communication using high-frequency radio waves (such as those on the 2.4 GHz and 5 GHz frequency bands) and comply with IEEE 802.11 standards. WLAN in our daily life refers to that implemented based on IEEE 802.11 standards. During the evolution and development of WLAN, various technical standards have emerged, such as Bluetooth, Wi-Fi, and HyperLAN2. Among them, Wi-Fi is now most commonly used due to its advantages such as simple implementation, reliable communication, high flexibility, and low implementation costs. Gradually, Wi-Fi becomes a synonym of WLAN.
Simply put, WLAN is a network system, while Wi-Fi is a technology in this network system. Therefore, WLAN includes Wi-Fi.
WiFi
refer to : https://info.support.huawei.com/info-finder/encyclopedia/en/WiFi.html
What Is WiFi?
WiFi, also known as Wi-Fi, is a trademark owned by the Wi-Fi Alliance (WFA). It is a WLAN technology based on the IEEE 802.11 family of standards. Since the release of the first-generation IEEE 802.11 standard in 1997, it has been evolved to the latest 6th-generation 802.11ax standard (Wi-Fi 6). Before the release of Wi-Fi 6, Wi-Fi standards were identified by versions from 802.11b to 802.11ac. Later, the WFA decided to make the Wi-Fi standards easier to understand and remember for Wi-Fi users and device vendors, and therefore renamed the standards using generational numbering.
What Does Wi-Fi Stand For?
When it comes to Wi-Fi, there are two major organizations you may have already heard of: IEEE and WFA.
The IEEE established the 802.11 Working Group to develop WLAN standards in 1990, and released the first 802.11 standard (802.11-1997) for WLAN in 1997. Since then, the IEEE releases a new standard every four to five years, the latest being the 6th-generation 802.11ax standard.
The WFA is a commercial organization that promotes and markets IEEE 802.11 standards as well as certifies the interoperability of 802.11 products worldwide. The WFA was originally founded to promote the formulation of the IEEE 802.11b standard. In 2000, the WFA announced its official name and adopted the term “Wi-Fi” as its trademark.
What does Wi-Fi mean? Currently, there are two arguments. One is that Wi-Fi stands for Wireless Fidelity, which is similar to High Fidelity (Hi-Fi) — a category of audio equipment. The other is that Wi-Fi has no specific meaning or full name. No organization has officially stated that Wi-Fi stands for Wireless Fidelity. Additionally, the name Wi-Fi is often written as WiFi or wifi, but these are not approved by the WFA.
Wi-Fi vs. WLAN
Wi-Fi is a trademark of the WFA, and is also a wireless network communication technology based on IEEE 802.11. The WFA has announced the use of Wi-Fi to improve the interoperability of products in compliance with IEEE 802.11 standards.
WLAN is short for wireless local area network. Quite simply, WLANs provide network communication using radio waves such as lasers and infrared signals, instead of physical connections. They provide wireless network communication using high-frequency radio waves (such as those on the 2.4 GHz and 5 GHz frequency bands) and comply with IEEE 802.11 standards. WLAN in our daily life refers to that implemented based on IEEE 802.11 standards. During the evolution and development of WLAN, various technical standards have emerged, such as Bluetooth, Wi-Fi, and HyperLAN2. Among them, Wi-Fi is now most commonly used due to its advantages such as simple implementation, reliable communication, high flexibility, and low implementation costs. Gradually, Wi-Fi becomes a synonym of WLAN.
Simply put, WLAN is a network system, while Wi-Fi is a technology in this network system. Therefore, WLAN includes Wi-Fi.