URLConnection is a class in the Java programming language that allows developers to connect to a resource identified by a URL. It provides methods to read from and write to the resource, enabling communication over the internet or local networks. This class is part of the java.net package and supports various protocols, including HTTP and FTP. When using URLConnection, developers can set request properties, manage timeouts, and handle input and output streams. It simplifies the process of retrieving data from web servers or sending data to them, making it easier to build networked applications in Java.