What is SFDX - Salesforce Developer eXperience

What is Salesforce Developer eXperience(SFDX):

1. SFDX is both a new set of tools and new features affecting the development life cycle.
2. SFDX help to shift the source of truth from production to VCS repository.

Org based development vs. source driven development:  

1.       In a traditional SF Dev Lifecycle, application builders use sandboxes to create and test changes. The source of truth is either production or any sandbox containing the most recent version of code and customization. 
2.       With Salesforce DX, you might use source driven development using the latest versions from a centralized source control system like GIT or SVN or PRODUCTION org.

SFDX concepts:

• SFDX CLI – command-line interface tools, for executing commands like > sfdx force:doc:commands:list
• Unlocked packages are intended to provide a repeatable, scriptable and trackable vehicle for introducing and managing change in your orgs. 
• Scratch Org is a temporary organization created from DevHub 
• DevHub feature can be enabled on production or tried in SFDX Trial Org