When you add a link to some sites like Facebook, you will notice the facebook is displaying some images for you to add it with your post. This usually known as Web scraping which allow you to parse the content then extract data from this content .This data could be an images, link or anything else.See examples below.
LinkScaper In general depending on Open Graph Protocol, So it first check if the page contain the og Metadata or not. If yes it will bring all the og:image then display to you otherwise it will bring all html images <img..>
- Creating a Nuget Pacakge so you can use it in your MVC or WebForms project.
- Creating a Tag Helper for ASP.NET Core.