Pickup times allow you to specify the days and times your customers can pickup their orders.
Offsets allow you to specify a minimum period of time a customer should allow before picking up their order. For example, if you are selling fresh produce you may decide to use this feature to allow time for your team to bake, create or prepare the order.
Breakpoints allow you to have two offsets per day. So, if you wanted to allow your customers to pickup their order the next day, if they order before noon and require two days notice if ordered after 2pm, then you would set a Breakpoint for this.
With Store Pickup + Delivery by default, every day of the year is eligible for pickups. But at some point within the year you will want to take a break and so you need the ability to prevent customers from ordering on days your store is closed. This is what you would use the Zapiet Blackout Dates feature for.