Niagara / Cascade differences and which to use?

Hope everyone is having a fantastic day so far!

I’m new to UE, that said what are the differences between Niagara / Cascade for game VFX?
Would it be worth it to learn Cascade now that Niagara has come out. Do these do the same thing?

Niagara replaces Cascade. Cascade is deprecated.

Thank you very much!

Niagara will be replacing Cascade very soon, eat up as many tutorials as possible!