When you sit down to plan a party and work out how many cups you need, where you'll put the chairs, and what time you'll start cooking, you are working out the logistics — the necessary details.
Logistics can describe difficult, technical operations. Many colleges have departments of logistics, which teach students how to plan for complicated events, like wars. The term is often used in military contexts to describe how to get soldiers to a certain place with enough food, toilet paper, guns, ammunition, and transportation. You'll often hear logistics used in regular speech to describe any effort that requires some prior planning — even if it's just the logistics of picking someone up at the airport.