Preload classes are special classes which load data from the web before the user requests it. It is a technique used by web developers to optimize the delivery of content to the user. Preload classes ensure that the page content is ready and available as soon as it is requested by the user. This helps to speed up the loading time of the page, as the data is already available in the background. Preload classes are usually used for large chunks of data that need to be preloaded on the page, such as videos, documents, images, and audio files. This helps to reduce the number of requests that need to be made to the server each time the page is requested. As such, preload classes help to reduce the overall loading times and provide the user with a better experience. In addition to optimizing page loading times, preload classes can also provide additional security to the page. By preloading data, it is harder for malicious actors to gain access to sensitive data. As such, preload classes can offer an additional layer of security to the page. Overall, preload classes are an important optimization technique that can help to speed up page loading times and improve security on the page. By preloading data, web developers can ensure that their page loads faster and offers users a better experience.