There used to be several client side languages, however, now almost all client side programming is done with JavaScript.
JavaScript is a scripting language which directly interacts with the web browser. All of the interaction is done on the client’s side. It is most often used for simple things like form validation and moving items around on the screen. However, it is being used for more now.
Client side programming is done inside of the script tag, either directly, or in an external file referenced by the script tag, such as is seen in the example below.
<script src="./scripts/my-script.js"></script>A web designer might use an external file for their scripts for the same reason why they would use an external file for CSS. So it can be downloaded separately, cached for faster access, and be used across multiple files easily.
Regardless of what is being done, or how, any changes made on the client web page occur independently of the web server, and not necessarily with its knowledge.
Through the process known simply as AJAX, JavaScript can be used to retrieve data from the server and then dynamically manipulate the client side page to update it with the new content.
Several frameworks exist to make this process even easier. It used to be semi-complicated to parse through the information and update the pages. The jQuery library, and others like it, made it easier to work with the programming, hiding some of the complexity.
Then some frameworks made it even easier. Each one has their own merits and drawbacks. React, Vue,js, and others work to automate the process for manipulating the client web page.
The changes made by JavaScript occur only on the web page, and are not stored anywhere. In fact, in many cases, reloading the webpage will see those changes undone unless the user performs the same, or at least similar, steps to recreate what they have done to modify the page.
The advantage of using this technique is the web server does not have to send as much data between the client and server. This reduces the amount of transmitted data, and allows for a faster website. It also means that they can handle more clients at a single time because the website is not sending as much data, and/or their expenses for transmitting data will be lower.
All of these reasons are why many websites are moving to incorporate client side programming for more than just form validation like it was relegated to for so many years.
Client Side Programming on your Webpage was originally found on Access 2 Learn
