What is eCommerce CRM? Can I manage All users in my eCommerce website by admin panel?

CRM is a tool for managing and maintaining relationships with customers in a B2C sector. E-commerce CRM solutions allow you to register, track and use data related to customer interaction. As for your second question - I'm not too sure about ready-made solutions but if you decide to develop a custom CRM for e-Commerce from scratch, you can do that. There are a lot of benefits of a custom CRM, such as sales growth, improved demand and supply planning, targeted marketing and advertising campaigns etc. You can take a look at this article and learn more about a custom CRM's advantages.