Flow

Salesforce has historically provided several declarative tools to implement business processes and custom user experiences, such as Workflow and Process Builder. Flow is now the recommended tool by Salesforce for all such automation. End user operations such as creating, updating, or starting an approval process for a record can be customized using Flow. When you need to implement a web-based experience that provides a wizard- or interview-style user experience, you can also use the Flow tool. Flow can be used to define complex conditional business processes that need to read and update records. Automation flows, sometimes referred to as “headless Flows,” are Flows that do not interact with the user and can also be called from within Apex code.

Flow lets you build engaging UIs but has its limits since it is not a programming language in a traditional sense. This does not mean, however, that if you or your users hit a roadblock you have to abandon it....