This week I have learnt some now technologies about the Internet and how to build up Internet-based applications, which are the client-side technologies such as XHTML, CSS and Javascript. For a new comer as me, in this week, it is just a brief glance at them, but I’d like to talk a little about them now.
As we known, the internet can be divided into two parts: the client side using web browser to parse the languages like XHTML, CSS and Javascript, and server side on which the PHP, Java and database are deployed. In this way, it is much more reasonable to start the journey of programming from the client side which is directly interactive with human beings.
XHTML is short for the ‘eXtensive HyperText Markup Language’ is a family of XML markup language that is the extended version of the widely used HyperText Markup Language (HTML), the language in which web pages are written. It is stricter than the former HTML and, nowadays, gradually replaces HTML.
At the beginning, the developers wrote codes using HTML both for the texts and formats of web pages. Later, they found there were plenty of duplicate workloads on writing the same format codes for relevant and consecutive pages.
Therefore, a new concept was introduced in this area which is called ‘Cascading Style Sheets’ (CSS). While HTML only focuses on the content of the text, the responsibility of CSS is to design the layouts. Because the file which contains the CSS is always embedded or outside the HTML files, it becomes very convenient for programmers to uniform and change the layouts without doing the same work again and again.
But only using HTML and CSS, the web page is static and cannot interact with users. How to make a dynamic and interactive website? The programming experts began to search some methods which could solve this issue. Some of them decided to use the language ‘Javascript’ which is also implemented as part of the web browser in order to provide enhanced user interfaces and dynamic websites.
Javascript and Java both use the similar syntax and the object-oriented concept from C. But the two languages are unrelated and have very different semantics. The advantage of using Javascript is that it works on the client side so that it could be interpreted very fast than any other languages which work on the server side.
