Angular

**** HttpClient ****

- HttpClient introduced in Angular4.x.

- HttpClient Eazy to Use Comapared to Http.

- HttpClient Applications are More Tastable Applications Compared to Http.

- HttpClient Applications are more deguggable Applications Compared to Http.

- Application Performance will be Improved.

- HttpClient Supports the Interceptors.

- HttpClient used to connect to servers via Http Protocol.

- HttpClient will convert the Response to JSON Format Automatically.

- HttpErrorResponse Used to Categorize the Errors.

- HttpClient present in HttpClientModule.

- HttpClient, HttpClientModule, and HttpErrorResponse Present in
  @angular/common/http module.


Interceptors:
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- Interceptors are used to filter the Http Req's before Hitting
  Server.

- Interceptors are used to validate the Req's Before Hitting the
  Server.

- "HttpInterceptor" is the interface used to implement the Interceptors.

- intercept() is the unimplemented method in Interface.

- intercept() used to validate the request's.