The main purpose of AJAX is to update the content on the product or layout of the website without disturbing the complete page. Usually, all the elements on the page are requested to update the page or load it, as it brings it from the server to display on the page. But with the help of AJAX, the customers can get the convenience of loading the pages which are different or need revision. As a result, the user gets to have a high-quality experience. Some of the experts call it one version of the server calls, as it will not refresh the entire page except for the needed changes. The Google maps are a good example of the AJAX. In simple words, it updates the page without making unnecessary changes.
Document Object Model (DOM)
If you want to make a career in the field of the SEO, you will be expected to know about the DOM, as famous search engines use it to break down the page and to assess it. In simple words, it is the steps the browser will continue once the HTML document for the page display has been received. After receiving the HTML document, the assessment of the content is initiated to get the relevant sources. For instance, the CSS and Java files will be fetched. Therefore, DOM can be called as the form achieved once the evaluation of the content and resources is finished. Some of the experts call it the organized form of the web page. Even though the nature of the DOM has changed if one compares it with the past, as the HTML has become dynamic, it is still manageable. In simple words, it is the feature that can change the content of the page in accordance with the user input or environmental factors.
It concerns with the actions related to the web page in the absence of the user interface. The reason for stressing this point is that Google allows the headless browsing to get the deeper understanding of the experience given to the user, especially if it is based on the content of the page. There are scripted browsers called phantomJS and Zombie for the purpose of automatic web interaction and to deal with the HTML snapshots.