HttpClient is a class in the System.Net.Http namespace used in .NET applications to send HTTP requests and receive HTTP responses. It simplifies the process of interacting with web services by providing methods for common operations like GET, POST, PUT, and DELETE. This makes it easier for developers to work with APIs and retrieve or send data over the internet. One of the key features of HttpClient is its ability to handle asynchronous operations, allowing applications to remain responsive while waiting for network responses. It also supports various configurations, such as setting headers, managing cookies, and handling timeouts, making it a versatile tool for web communication in software development.