Each listing carries its own delivery method. Your store settings are the default; the listing is where it is actually decided.
That matters because a store rarely sells only one shape of thing.
The three families
You send it. A courier, or your own delivery if you do that locally. The ordinary case.
Pickup only. Collection from one of your pickup points, no posting. What is a pickup point?
The buyer arranges. They send their own courier or driver — for furniture and anything a parcel network will not take. Sending your own courier or driver
When to use each
Pickup only for anything heavy, fragile, perishable, or that a courier would refuse. It is not a lesser option — for pottery, plants and glass it is the one that works. Why some items can only be collected
Buyer arranges for furniture and large awkward things, where no parcel rate would be honest.
You send it for everything else.
Why per-item rather than per-store
Because a store selling earrings and lampshades has two completely different delivery problems. One rate across both overcharges the earrings and loses money on the lampshades — and the lampshade loss is invisible until you compare what the courier billed with what you charged.
Setting it per item is how you stop subsidising your own bulky stock. Should I offer free delivery?
The other half: which prices apply
A delivery option holds a price for each zone, and a listing uses one of them. Most stores need one; add a second when something in your range clearly does not fit the first. What is a delivery profile?
So two settings, doing different jobs: how it travels (on the item) and what it costs (the option it uses).
What the buyer sees
The methods available for that item, at checkout, with the price for their PIN code — before they pay. If an item is pickup-only they see that rather than discovering it afterwards. The four ways an item reaches you
The mistake to avoid
Leaving everything on the default because the default worked for your first item. The second time you sell something twice the size, the default is quietly wrong — and you will find out from the courier's correction on your balance. What is chargeable weight?
More: how to set delivery prices, how do I work out what to charge for postage, how to offer pickup.