Trigger.new Vs Trigger.newMap

What is the difference between Trigger.new & Trigger.newMap ?

Trigger.new : Returns list of the new versions of the sObject records

Trigger.newMap : A map of ID's to the new version of the sObject records.
Note : "Trigger.newMap" is available only in After Insert,Before Update,After Update.

Any workaround to use Trigger.newMap in Before Insert ?

Use below code to form the Map and use that in other places of logic.