Updating a web page

Abstract

Devices connect to a wireless local area network (WLAN) with Wi-Fi communication (see Chapter 7 (Wireless local area network)). A router connected to an Internet Service Provider (ISP), through a telephone line using DSL (Digital Subscriber Line) technology, provides access to the Internet (see Figure 8-1). The Internet is formed by interconnected computer networks using the Internet Protocol suite, consisting of the Transmission Control Protocol and the Internet Protocol (TCP/IP), to globally link devices. The World Wide Web (WWW) identifies information resources by URLs (Uniform Resource Locators). The client or web browser, such as Google Chrome or Mozilla Firefox, sends an HTTP (HyperText Transfer Protocol) request to the server device hosting the resource to retrieve information at the web address defined by the URL. The server responds to the client HTTP request, and the client displays the requested web page information on the Android tablet or mobile phone. The client must request web page information from the server, as the server cannot impose updates on the client. The exception is WebSocket, as discussed in Chapter 9.