Confused about passwords to use when Comcast emails are "migrated" to Yahoo

I received the invite to move to Yahoo and I am reviewing the instructions at

 https://help.yahoo.com/kb/SLN36803.html

Part of the initial steps for migration is creating a NEW STRONG PASSWORD

• One has to sign in at yahoo.com with one’s full Comcast.net email address and password 
• as shown in first video https://s.aolcdn.com/membership/help/000015905/xfinitymovetoyahoomail.mp4

at minute 1:30, one is directed to create a “new strong password for your account”.

Question:  What is this password for and when is this password supposed to be used? Is this a new password for the Yahoo email account being migrated from Comcast?? Does this mean that once this is entered, this password needs to be used for any future access for this email account, INCLUDING when adding Yahoo mail to Apple Mail on a Mac?   I am confused by the many different passwords during this transition, as later on I am told that one has to also create an App password for Apple mail (NOT icloud mail which I do NOT use). Can someone please help and clarify what the "new strong password" is for vs. the one time "app password" for Apple Mail?   I hope that I will be notified if an answer will be posted. Thanks.