What Is a Client-Server Connection?

Client (Client), or client, refers to the program that provides local services to clients corresponding to the server. Except for some applications that only run locally, they are usually installed on ordinary clients and need to run in coordination with the server ^[1] . After the development of the Internet, more commonly used clients include web browsers such as the World Wide Web, email clients for receiving and sending emails, and client software for instant messaging. For this type of application, there must be corresponding servers and service programs in the network to provide corresponding services, such as database services, e-mail services, etc. In this way, a specific communication connection needs to be established between the client and server to ensure The normal operation of the application ^[2] .

A client is also called a workstation (Workstation), which refers to a computer connected to the network. It is controlled and managed by a network server and can share various resources on the network. After the personal computer is connected to the Internet, it acquires Internet services and becomes a workstation on the Internet. Network workstations need client software running a network operating system ^[3]

The relationship between client and server may not necessarily be established on two separate

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When a user uses a domain name instead of an IP address to access network resources, the system resolves the domain name that needs to be accessed, that is, finds the IP address corresponding to the domain name. First query the local domain name information cache. If the query is successful, the corresponding IP address is returned, otherwise a DNS request is sent to the local domain name server. ^[4]

Web client mainly refers to the web browser (Browser). Its main function is to display the web resources requested by the user from the server and display them in the browser window. Resources are usually in html, pdf, image and other formats. The mainstream web page browsers are: Microsoft's IE, Mozilla's Firefox, Apple's Safari, Google's Chrome, and Opera's Opera ^[5]

A game client is software that stores many resources in a game. The player enters the instruction through the client, and the client translates the data and sends it to

The mobile client uses a mobile phone as an example. The mobile client is software that can be run on a mobile terminal. It is also a key development project in the 3G industry, which is of great significance.

With the advent of the 3G era, mobile Internet access has slowly entered people's lives. When it comes to the future development trend of wireless Internet based on mobile phones, whether it is mobile client access or mobile wap access, it is still too early for us to prematurely. Conclusive, but one thing is certain, the quality of the user experience will directly determine the future of the two.

Under the wireless Internet network environment and various conditions, mobile client access and mobile WAP access have their own advantages and disadvantages. The client software needs to be installed on the mobile phone to use; while using the WAP of the mobile phone to access the Internet, you need to manually enter the URL for the first time, which can be accessed more conveniently after saving the URL as a label ^[6]

The client uses queued calls according to Myc1ienthttpbridge. Myclienthttpbridge can be hosted with the client on the same process, on a different process, or on a separate server. The Myclienthttpbridge service uses WshttpBindIng to call the remote service. The client needs to retrieve the metadata of the remote Internet service (such as the definition of ImyContracthttpbridge) and convert it to a queue contract (such as IMyContract) ^[7]

To call the operation of the service, the client first needs to import the service contract into the client's NativeRepresentation. If the client uses WCF, a common practice for calling operations is to use a proxy. A proxy is a CLR class that exposes a separate CLR interface for representing service contracts. Note that if the service supports multiple contracts (at least multiple endpoints), the client needs a proxy for each contract type. The proxy not only provides the same operations as the service contract, but also includes methods to manage the life cycle of the proxy object and manage service connections. The agent completely encapsulates all aspects of the service: the location of the service, the implementation technology, the runtime platform, and communication transmission ^[8] .