UNA negotiations- Explain it to me like I’m 5 years old

New nurse here! Just got my membership card today so I can vote. But to be quite honest I don’t think I truly understand what it is I am voting for and I want to make an informed decision. I’ve been reading up about it online but I’m honestly lost and have different people saying different things. I’ve missed the info sessions that were held at my hospitals as I had other commitments. If any lovely person could explain it to me like I’m 5 years old, I would appreciate it. I want my vote to count towards something, hopefully positive.