# 13.0: API Intro

This section provides an overview on APIs. *Remember, this is different from the API we created to add the starred option.*

## Terms

* MVC: Model View Controller
* API: Application Programming Interface
* JSON: JavaScript Object Notation -- Something is serializing and de-serializing
* XML: Extensible Markup Language

## Discussion

* Eleven Note is an *n*-tier data application with an MVC presentation tier
* The services tier does not care that it's MVC
* The services tier allows us to have more presentation tiers
* An API is a set of calls that we'll expose to other programs through endpoints
* The API will serve to allow other presentation tiers to gain access to those service methods
* This way we can allow as many presentation layers as we want to access our data
* Web API uses the same routing engine as MVC

## Types of Web Service Communication Protocols

* REST: Representational State Transfer
  * JSON based
  * Uses verbs that represent the intent (GET, POST, PUT, DELETE)
* SOAP: Simple Object Access Protocol
  * XML based
* We will use REST 

## Postman

* Postman is an indispensable tool that helps us with testing
* It acts as a fake client for making requests - we can log in, add notes, update notes, and delete notes from the database
* It will allow us to:
  * Test the endpoints of the API
  * Make a request to an endpoint
  * Behave as a client (a web or mobile application) without having a user interface
* **Install** [**Postman**](https://www.getpostman.com/)

[Next,](https://eleven-fifty-academy.gitbook.io/dotnet-201-elevennote/elevennote-api-parts-13-19/part-13-api-intro/13.1-testlogin) we'll test the login page with Postman.