HI guo hua,

Developer Edition is ideal if:
You are a partner who intends to build a commercially available Force.com app by creating a managed package for distribution through AppExchange and/or Trialforce. - NOTE: Only Developer Edition or Partner Developer Edition environments can create managed packages.
You are a salesforce.com customer with a Professional, Group, or Personal Edition, and you do not have access to Sandbox.
You are a developer looking to explore the Force.com platform for FREE!

Sandbox is ideal if:
You are a salesforce.com customer with Enterprise, Unlimited, or Force.com Edition, which includes Sandbox.
You are developing a Force.com application specifically for your production environment.
You are not planning to build a Force.com application that will be distributed commercially.
You have no intent to list on the AppExchange or distribute through Trialforce.

Production is ideal if:
Production Force.com environments store the live data that is actively used to run your business.  Sandbox is a nearly identical copy of your production environment available to Enterprise or Unlimited Edition customers. The sandbox copy can include data, configurations, or both. It is possible to create multiple sandboxes in your production environments for a variety of purposes without compromising the data and applications in your production environment.

If you have any doubt, I have attached a link and through this link, you can take deep knowledge.

https://developer.salesforce.com/page/An_Introduction_to_Environments (https://developer.salesforce.com/page/An_Introduction_to_Environments)

If that above link would helpful for you so please choose my and as the best answer.

Thanks,
Harshit Garg
harshitgarg2591@gmail.com