The Components Library on the right sidebar contains all of the available components. Use this to drag-and-drop a component from the library to the canvas. It organizes components into sections and you can enter a search term to quickly find a component you need.
Check the Components Catalog here to know more about specific component.
Component Config Inspector
The Component Config Inspector is also called as component inspector. It contains all the available settings for the selected component and is where you set values, update component names, and create event handlers. The Compoenent Inspector organizes settings into different sections, such as Property and Styles.
To open the Component Config Inspector, click on the component handle that is present on the top of the component including ⚙️ + Component Name and the component inspector will open up on the right side: