Meteor run vs meteor run --production?

meteor run vs meteor run --production?
Should be I use?
Please help me.

Try meteor run --help in the terminal to see a brief description of this.

• meteor run = start your in dev environment , alot of js files and one css file
• meteor run --production , start your app in production environment, but just simulate, not really production. Meteor build 2 files: 1 js file and 1 css file