The standard approach to access and perform CRUD operations (Create - Read - Update - Delete) with SharePoint data is to use SPHttpClient. We did already use SPHttpClient when working with our first real web part in Chapter 4, Building your First Web Part. Next, we are going to be focusing more deeply on the use of SPHttpClient, but you should know that it is not the only way to work with SharePoint data while you are using the SharePoint Framework. SPHttpClient is built into the SharePoint Framework to perform REST calls against SharePoint, but you can do the REST calls using some other framework (e.g. jQuery) or simply using JavaScript's XMLHttpRequest object. In addition to REST-based approaches, you can use SharePoint JSOM, a JavaScript Object Model which is a subset of the SharePoint client-side object model first introduced in SharePoint 2010.
Using an object model instead of REST is a habit of SharePoint old-timers. Back in the good old...