ServiceNow GlideRecord: initialize versus newRecord

initialize documentation > Creates an empty record within the current GlideRecord that is suitable for population before an insert
> isNewRecord=false before insert, gs.info(gr.Active) is empty before .insert()

newRecord documentation > Creates a GlideRecord, sets the default values for the fields, and assigns a unique ID to the record
> isNewRecord=true before insert,  gs.info(gr.Active) is populated before .insert()

>fairly helpful video link here

in a nutshell,
isNewRecord() allows you to query values / perform validation before the insert (e.g. if you wanted to include conditions) and populates the records holding the values in memory
in the rare case for example you wanted to create/update a related record (e.g. in a custom table) BEFORE the insert operation, newRecord() enables values to be referenced

example:

var gr=new record ('incident)';

gr.initialize() / gr.newRecord()

gs.print(gr.active);
gs.print(gr.sys_id);
gs.print(gr.number);
gs.print();

gr.insert();

===

from Chuck Tomasi in this article,

"

• initialize(): Creates an empty record suitable for population before an insert.
• newRecord(); Creates a GlideRecord, set the default values for the fields and assign a unique id to the record.

Try these two in scripts background and you'll see that initialize gives no value to opened_at, whereas newRecord does.

var inc = new GlideRecord('incident');

inc.initialize();

gs.print(inc.opened_at.getDisplayValue());

var inc = new GlideRecord('incident');

inc.newRecord();

gs.print(inc.opened_at.getDisplayValue());

I have always trusted newRecord more since learning about this a few years ago."

(ServiceNow )