Can anyone describe the CRUD operations by admin panel ?
CRUD Models in Magento 2 can manage data in database easily, you don’t need to write many line of code to create a CRUD. CRUD is stand for Create, Read, Update and Delete. We will learn about some main contents: How to setup Database, Model, Resource Model and Resource Magento 2 Get Collection and do database related operations. Here's Creating Hello World Module
To understand CRUD Operation. you can refer below link, where crud explanation is quite good and simple.