The number of IIS or WEB connections refers to the number of accesses the server can accept at the same time. It can be simply understood as how many browser windows are allowed to open to access your website at the same time.
![2477293_1[1].jpg](http://www.lhynn.cn/upload/default/20181018/cecb393322eee907848d2c9661db7fec.jpg "2477293_1[1].jpg")
![2477293_2[1].jpg](http://www.lhynn.cn/upload/default/20181018/77dfedace7d6bce92f9ee63d04b767d9.jpg "2477293_2[1].jpg")
When a web page is viewed, the server establishes a link with the viewer's browser, and each link represents a concurrency. When a page contains many images, the images are not displayed one by one. The server will generate multiple links and send text and images at the same time to improve browsing speed. If there are more images on the page, the more concurrent links the server has. When a picture or page is sent by the service, the server closes the link for establishing a link with other requesters. Each concurrency is almost instantaneous and typically takes between a few milliseconds and tens of milliseconds.
![2477293_3[1].jpg](http://www.lhynn.cn/upload/default/20181018/4869682b823711925a28c6999e91cfa3.jpg "2477293_3[1].jpg")
![2477293_4[1].jpg](http://www.lhynn.cn/upload/default/20181018/8abd122e2b656d6949b5bbe5aee3adbc.jpg "2477293_4[1].jpg")
In general, an IE browser generates 2 IIS connections. For example, we observed a peak value of 1800 on a server with a traffic of 260,000 IP per day. It means that about 900 IE browsers are connected to your server at the same time.
![2477293_5[1].jpg](http://www.lhynn.cn/upload/default/20181018/d3dddb7dd801dc002de116ae18785166.jpg "2477293_5[1].jpg")
