What is a web browser

Web browser refers to a "web browser", an application used to retrieve, display and deliver Web information resources; simply put, it is software used to browse web pages. Web browsers mainly interact with web servers and obtain web pages through the HTTP protocol. These web pages are specified by URLs. The file format is usually HTML and specified by MIME in the HTTP protocol. A web page can include multiple documents, and each document is obtained from the server separately.

The operating environment of this tutorial: Windows 7 system, Dell G3 computer.

Web means "network". A web browser refers to a web browser, which is software used to browse web pages.

web browser (web browser)

Web browser (English: web browser), often referred to as a browser, is An application used to retrieve, display, and deliver Web information resources. Web information resources are marked by a Uniform Resource Identifier (URI), which is a web page, a picture, a video, or any content presented on the Web. Users can use hyperlinks to browse related information through the browser.

Web browsers mainly interact with web servers and obtain web pages through the HTTP protocol. These web pages are specified by URLs. The file format is usually HTML and specified by MIME in the HTTP protocol. A web page can include multiple documents, and each document is obtained from the server separately. Most browsers natively support a wide range of formats in addition to HTML, such as JPEG, PNG, GIF and other image formats, and can extend support for numerous plug-ins. In addition, many browsers also support other URL types and their corresponding protocols, such as FTP, Gopher, and HTTPS (encrypted version of the HTTP protocol). HTTP content types and URL protocol specifications allow web designers to embed images, animations, videos, sounds, streaming media, etc. in web pages.

Composition of the browser

1. Address bar: used to enter the address of the website. IE browser recognizes the address bar The information in the content correctly connects the content that the user wants to access. To log in to the "Website Home" website, just enter the URL of Baidu Home in the address bar: https://www.baidu.com/, and then press the [Enter] key or click the button on the right side of the address bar. Can. The address bar also comes with shortcut buttons for commonly used commands in IE, such as refresh (C), stop (x), etc. The forward and back buttons are set in front of the address bar.

#2. Menu bar: It consists of "File", "Edit", "View", "Favorites", "Tools" and "Help" menus. Each menu contains related command options to control the work of IE. These options include all operations and setting functions of the browser.

3. Tabs: Starting from Internet Explorer 8, IE can use multi-tab browsing to open website pages in tabs.

#4. Page window: It is the main window of IE browser, where the content of the visited web page is displayed. Some text or objects on the page have hyperlink attributes. When the mouse pointer is placed on it, it will turn into a hand shape. Click the left mouse button and the browser will automatically jump to the URL pointed to by the link; click the right mouse button. A shortcut menu pops up, from which you can select the operation command to be executed.

5. Status bar: Displays the current operation and the progress of downloading the Web page in real time. When a web page is opening, the progress of opening the website will also be displayed. In addition, the web page can be zoomed in and out through the status bar.

Browser kernel

There are many types of browsers, but there are only four mainstream kernels. Various browsers are based on the mainstream kernel. Add different functional components.

1. Trident kernel

The representative product is Internet Explorer, also known as IE kernel. Trident (also known as MSHTML) is a typesetting engine developed by Microsoft. Browsers that use the Trident rendering engine include: IE, Maxthon, World Window Browser, Avant, Tencent TT, Netscape 8, NetCaptor, Sleipnir, GOSURF, GreenBrowser and KKman, etc.

2. Gecko kernel

The representative work is Mozilla Firefox. Gecko is an open source web page layout engine written in C. It is one of the most popular layout engines, second only to Trident. The most famous browsers that use it are Firefox and Netscape 6 to 9.

3. WebKit core

Representative works include Safari and Chrome. WebKit is an open source project that includes some components from the KDE project and Apple. It is mainly used in Mac OS systems. It is characterized by a clear source code structure and extremely fast rendering speed. The disadvantage is that the compatibility with web page codes is not high, resulting in some non-standard web pages being unable to display properly.

4. Presto core

represents the work Opera. Presto is a browser layout engine developed by Opera Software for use with Opera 7.0 and above. It replaces the Elektra layout engine used in the old Opera 4 to 6 versions, including adding dynamic features. For example, web pages or parts thereof can be rearranged according to DOM and Script syntax events.

Mainstream browser classification

There are currently a variety of web browsers. Some web browsers use plain text interfaces and they only support HTML; some web browsers have rich and colorful user interfaces and support multiple file formats and protocols. Web browsers that support e-mail, newsgroups, and IRC through components are sometimes called "network packages" rather than just "web browsers."

All major web browsers can open multiple information resources through multiple windows or multiple tabs at the same time, and can also block pop-up ads to prevent unnecessary windows from opening without the user's consent. pop up.

Mainstream browsers are divided into several categories such as IE, Chrome, Firefox, and Safari. They have the following characteristics:

1. IE browser. The IE browser is a browser launched by Microsoft that comes with the Windows system. Its kernel is independently developed by Microsoft, referred to as the IE kernel (Trident kernel). This browser only supports the Windows platform. Most domestic browsers provide some plug-ins based on the IE core, such as 360 Browser, Sogou Browser, etc.

2. Chrome browser. Chrome browser is a browser independently developed by Google on the basis of open source projects. The core is WebKit and has the largest market share. It also provides many plug-ins that are convenient for developers to use. Therefore, this browser was also developed in this book. of major browsers. The Chrome browser not only supports Windows platforms, but also supports Linux and Mac systems. It also provides mobile applications (such as Android and iOS platforms).

3. Firefox browser. The Firefox browser is an open source browser provided by an open source organization, with the core Gecko. It open source the source code of the browser, and also provides many plug-ins to facilitate users' use. It supports the Windows platform, Llnux platform and Mac platform.

4. Safari browser. The Safari browser is mainly a browser tailor-made by Apple for the Mac system. The core is WebKit and is mainly used in Mac and iOS systems.

For more related knowledge, please visit the FAQ column!

The above is the detailed content of What is a web browser. For more information, please follow other related articles on the PHP Chinese website!