Share Vs Email when modifying the videos permissions

we have these 2 scenarios:-

1) we have a video which we want all users inside our orgnazation to be able to view it, but not modifiy it or delete.

2) second scenario we have a video which should only be visible to specific users.

nowi access the videos inside the MS Stream admin >> and seems i have 2 options to share the video, either using "Share" Or "Email" as follow:-

so what are the differences between these 2 options? and how i can achieve the above 2 scenarios?