Salesforce DX, used primarily by developers, allows users to have true version control. Version control allows developers to have better control over collaboration, auditing, and disaster control. It is also an important part of an agile release plan. It also helps users build and release new features quickly and with minimal risks.
Salesforce DX combines features from Force.com and Heroku Flow along with new improvements. DX uses the migration tool from Force.com to retrieve and push metadata to an org, also known as a developer environment, but DX also pulls all functionality into one place. DX delivers integration and application pipelines that help streamline workflow through Heroku Flow.
Salesforce DX introduces a new type of Salesforce environment in Scratch orgs. These are orgs consisting of Salesforce code or metadata that can be easily created or destroyed, helping to speed up the standard development workflow.