How do I store breast milk?

Brittany • Mama of a beautiful baby girl and another lil babe on the way💕

I know I can store breast milk in the fridge that would have to be drank by on/by the 4th day but what about freezing it? On the 4th day can I then move it to the freezer off it won’t be used in time of expiration? Any advice would help! Totally new to this breastfeeding journey