There are multiple common situations where Proxies are used. We talked about some of them in the beginning of this chapter. Based on how the Proxies are used, we can categorize them as virtual proxy, remote proxy, protective proxy, and smart proxy. Let's learn a little more about them in this section.
Here, you'll learn in detail about the virtual proxy. It is a placeholder for objects that are very heavy to instantiate. For example, you want to load a large image on your website. Now this request will take a long time to load. Typically, developers will create a placeholder icon on the web page suggesting that there's an image. However, the image will only be loaded when the user actually clicks on the icon thus saving the cost of loading a heavy image in memory. Thus, in virtual proxies, the real object is created when the client first requests or accesses the object.