HttpClient instance was used to invoke or consume the external rest API by clients like console applications or web applications. What Is Socket?: A Socket is a system communication protocol providing a communication channel over TCP connection. In programming, terminology socket can be defined as the combination of Url and Port Number to make communication channels. HttpClient Working Flow: Let's assume that we have .Net Core application, which will consume an external API using HttpClient. The steps involved in communication are as follows: The user requests our application, in which we need to call an external API to serve results to the user. On receiving user request our application creates an instance of HttpClient. Next HttpClient looks for HttpRequestHandler object in the pool of HttpRequestHandlers. Then HttpClient picks up one of the HttpRequestHandler objects and gives all input information like Url, payload, tokens, etc to make an external API call. Then HttpRequest