Salaesforce Einstein Prediction Builder is a declarative tool that helps fast-track predictions based on Salesforce fields. This will help a Salesforce admin to custom-build predictions on any object via few clicks on a visual interface and power workflows and apps using the newly-found AI.
Salesforce Einstein Next Best Action uses strategies that apply your org's business rules to display context-sensitive suggested offers and actions on your Lightning record pages. Suggested Actions brings the power of Einstein Next Best Action into Communities.
Go through this vidoe to learn more about Einstein Prediction Builder and Einstein Next Best Action.