die Lieferung
delivery
The process of transporting and delivering goods to a recipient.
Die Lieferung der bestellten Bücher erfolgt innerhalb von drei Werktagen.
Delivery of the ordered books takes place within three business days.

delivery
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delivery
The process of transporting and delivering goods to a recipient.
Die Lieferung der bestellten Bücher erfolgt innerhalb von drei Werktagen.
Delivery of the ordered books takes place within three business days.

'Die Lieferung' (the delivery) is derived from the verb 'liefern' (to deliver). The ending '-ung' forms a feminine noun that describes the action of the verb (the delivering) or its result (the delivered goods).
Wir warten auf die Lieferung unserer neuen Möbel.
We are waiting for the delivery of our new furniture.
Context tells you whether the process (meaning 1) or the goods (meaning 2) are meant. If it is about time, costs, or transport, it is the process. If it is about unpacking, checking, or the contents, it is the goods.
Die Lieferung hat drei Tage gedauert.
The delivery took three days.
When it is about the process of delivering, you often hear 'schnelle Lieferung' (fast delivery), 'kostenlose Lieferung' (free delivery), or 'Lieferung frei Haus' (delivery free to your door). Typical verbs are 'erfolgen' (to take place) or 'sich verzögern' (to be delayed).
Die Lieferung der Pizza sollte in 30 Minuten erfolgen.
The delivery of the pizza should take place in 30 minutes.
When the goods are meant, typical verbs are 'eine Lieferung annehmen' (to accept a delivery), 'eine Lieferung erhalten' (to receive a delivery), or 'eine Lieferung kontrollieren' (to check a delivery). It is also often combined with adjectives like 'frisch' (fresh) or 'beschädigt' (damaged).
Der Koch hat die frische Lieferung Fisch sofort kontrolliert.
The cook immediately checked the fresh delivery of fish.
program / shipment
'die Sendung' and 'die Lieferung' can both refer to goods that are sent to someone. 'Sendung' emphasizes the shipped unit more, for example one package or several packages with a number. 'Lieferung' can refer to the goods themselves, but also to the process of bringing them. Learners may confuse the words because both appear in contexts involving mail, online orders, and goods. When the focus is on transport and arrival, 'Lieferung' is often more natural; when the focus is on the shipped package or the tracking number, 'Sendung' fits well.

Lukas wartet am Montag auf die Lieferung der neuen Möbel.
On Monday, Lukas is waiting for the delivery of the new furniture.
Mit der Nummer kann ich die Sendung im Internet verfolgen.
With the number, I can track the shipment online.