Sorry for the new guy question, I've seen a ton of talk about this but I think I am missing some subtlety. I was wondering what the differences are between Reserve and Line holders. I see a lot of talk about WB new hires going to have to sit Reserve for years on the 777 out of EWR. Is that a terrible thing. Isn't reserve guaranteed like 73 hours pay per month? I understand the differences between LCR and SCR. Is a new hire just stuck on SCR and that is what sucks?

I am coming off of AD military and I wouldn't mind a slower pace on the flight schedule at least for a hot minute. I would ideally be living in base however we are thinking about commuting so that I can put the kids and wife nearer to family.
Thank you for any insight.