1, front-end concept
The front end is the front part of the website, which runs on browsers such as PC and mobile, and displays web pages for users to browse. With the development of Internet technology and the application of HTML5, CSS3 and front-end framework, cross-platform responsive web page design can adapt to various screen resolutions, improve dynamic design, and bring users a very high user experience.
2, front-end function
Front-end technology is generally divided into front-end design and front-end development. Front-end design can generally be understood as the visual design of the website, while front-end development is the realization of the front-end code of the website, including basic HTML and CSS, JavaScript/ajax, the latest advanced versions of HTML5, CSS3 and SVG.
3. Main front-end technologies: HTML, CSS and JavaScript.
These three skills are the most basic and necessary skills in front-end development. In the front-end development, in the layout of the page, HTML defines the elements, CSS locates the displayed elements, and then JavaScript realizes the corresponding effects and interactions. Although the surface looks simple, there is absolutely no shortage of things to master. Before development, we need to clarify and understand these concepts in order to be handy in the development process.
（ 1）HTML
It refers to hypertext markup language, which is also the most commonly used general language in our web pages. After several versions of development, it has developed to version 5.0. Due to the standards and specifications established by W3C, it has been generally upgraded to XHTML. XHTML refers to Extensible Hypertext Markup Language. XHTML became W3C standard on June 26th, 2000, which is a stricter and purer HTML code. The goal of XHTML is to replace HTML. XHTML is almost the same as HTML 4.0 1. XHTML has been redefined as an XML application, which is a W3C standard. W3C defines XHTML as the latest HTML version. All new browsers support XHTML.
CSS
Cascading style sheets are referred to as "CSS" for short, and are often called "style sheets", which are used to design the style of web pages. For example, if you want the linked word to be blue when it is not clicked, it will turn red and underlined when the mouse moves up. This is a style. By setting the style sheet, you can uniformly control the display properties of each logo in HTML. Cascading style sheets can make people control the appearance of web pages more effectively. Using cascading style sheets, you can expand your ability to specify the location and appearance of web page elements accurately and create special effects.
JavaScript
It is an object-oriented, dynamic and case-sensitive client scripting language developed by Netscape's LiveScript. Its main purpose is to solve the speed problem left by server-side languages (such as Perl) and provide customers with a smoother browsing effect. At that time, the server needed to verify the data, because the network speed was quite slow, only 28.8kbps, and the verification step wasted too much time. So Netscape's browser Navigator adds Javascript to provide the basic function of data verification.
Second, what is the back end?
1, back-end concept
Most back-end developers are committed to building the actual logic behind the applications they develop. Front-end developers build the user interface, while back-end developers write code to make it work. Back-end developers write code that makes buttons work by pointing out what data is extracted from the database and sending it back to the front end. Back-end developers may also participate in the system architecture and decide how to organize the logic of the system so that it can be maintained and operated normally.
May participate in building a framework or system architecture to make it easier to write programs. Back-end developers spend more time implementing algorithms and solving problems than front-end developers. Usually, front-end development work is more about creating user interfaces and related content than implementing actual business logic to make applications work.
2. Main technologies of back-end development
Front-end developers need to know a series of tools for creating user interfaces, while back-end developers usually use a completely different set of tools and skills to get the job done efficiently. An important skill that back-end developers need is related to SQL and databases. Most back-end systems need to connect to a database that stores application data.
Back-end developers usually write, read and process data from databases or other data sources, so it is very important to have skills such as SQL. Back-end developers-at least for Web development-also need to be good at the server-side language they use in technology stack.
Back-end developers need to know more about the application architecture, because in most cases, back-end developers need to build the architecture and internal design of the application. A good back-end developer needs to know how to use various frameworks and libraries, how to integrate them into applications, and how to build code and business logic in a way that makes the system easier to maintain.
The front-end user's visual interface, the front-end page of the website is the page development of web pages, and the front-end work content is to design the renderings of art design into web pages that the browser can run, and cooperate with the back-end to do visual work content such as data display and interaction of web pages; Backend refers to what users can't see, usually interacting with front-end engineers and saving and reading website data. Relatively speaking, the back-end involves much more logic codes than the front-end, and the back-end considers the implementation of the underlying business logic, the stability and performance of the platform, etc.
The above is the specific difference between the front-end and the back-end. I hope I can help you!